Devices and methods for anchoring a sheath in a tissue cavity

ABSTRACT

According to some embodiments of the invention, an anchoring system includes a sleeve having an inner surface defining a first lumen, a first annular sealing mechanism disposed at a proximal end of the sleeve, and a second annular sealing mechanism disposed at a distal end of the sleeve. The anchoring system further includes a pressure tube in fluid connection with an outer surface of the sleeve, a sheath in mechanical connection with the sleeve, the sheath forming a second lumen, the second lumen being in fluid connection with the first lumen, and open-cell foam disposed on the outer surface of the sleeve. Application of negative pressure to the pressure tube causes a seal to form between the first and second annular sealing mechanisms and an inner surface of a tissue cavity. Application of negative pressure to the pressure tube also creates a frictional force that resists displacement of the sleeve.

This application claims priority to U.S. Provisional Application No.62/283,877 filed Sep. 15, 2015, the entire content of which is herebyincorporated by reference.

BACKGROUND 1. Technical Field

The field of the currently claimed embodiments of this invention relatesto medical devices, and more particularly to anchoring medical deviceswithin a tissue cavity.

2. Discussion of Related Art

The need for temporary protection of the bowel lumen from fecal flowafter surgical bowel resection and anastomosis or when the bowel wall isdamaged has traditionally been accomplished by the creation of anexternal diversion of the bowel through the creation of an ostomy. Anostomy is a purposeful anastomosis between a segment of thegastrointestinal (GI) tract and the skin of the anterior abdominal wall.An ostomy can be created virtually anywhere along the GI tract. Fordiversion of the fecal stream, the most common ostomies involve thedistal small intestine (e.g., ileostomy) and large intestine (e.g.,colostomy). Ostomies are performed in 300,000 patients in the US andover 2 million patients globally, but this surgery is complicated byhigh morbidity, mortality, and severe impact on a patient's quality oflife. Although many ostomies are intended to be temporary, as many as ⅓of temporary ostomies are never reversed. Accordingly, there is a needfor improved method and devices to provide a less morbid alternative forfecal diversion.

One of the major indications for a temporary ostomy is to protect abowel anastomosis from enteric contents that can lead to anastomoticleaks. An anastamotic leak is defined as a defect of the intestinal wallat the anastomotic site leading to a communication between the intra-and extraluminal compartments. Anastamotic leaks after bowel surgery isa major complication. The overall incidence of colorectal anastomoticleak varies widely in the literature, ranging from 1 to 24%. Leaks cancause severe complications such as loss of the anastomosis, sepsis, anddeath. Even in those cases where the anastomosis is salvaged, poorcompliance in the neorectum can lead to a poor functional outcome. Inmany large studies, anastamotic leaks has been shown to be associatedwith a pelvic sepsis at a rate of 50%. By protecting the anastomosisfrom fecal flow, anastamotic leaks may be prevented or their morbiditymitigated. In addition, even after an anastamotic leak has occurred,protection from fecal flow can make the anastamotic leak less severe andaid in healing of the leak. There are several risk factors for thedevelopment of an anastamotic leak. The most significant risk factor isthe level of the anastomosis, with the leak rate increasing as thedistance from the anastomosis to the anus decreases. Other thanmeticulous technique in creating the anastomosis, the major strategy toprevent and treat anastamotic leaks during complicated or high-riskcases involving bowel resection is to divert fecal flow. This isaccomplished by having the flow of gastric contents diverted using anostomy created in the bowel proximal to the anastomosis. Proximal in thebowel is defined as higher up in the GI tract towards the mouth, distalin the bowel is defined as lower down in the GI tract towards the anus.This ostomy can be either an end ostomy such as an end colostomy or endileostomy or can be a diverting loop ileostomy that does not completelydisrupt bowel continuity.

A temporary diverting ostomy and its closure has its own set ofcomplications and morbidities including dehydration due to high output,difficulty with ostomy care, stricture at the closure site, woundinfections, and incisional hernias. Complication rates of ostomies rangebetween 5% and 100%. The complications can be divided into minorcomplications, which do not require surgical intervention, and majorcomplications requiring surgical intervention. Major complicationsinclude stenosis, small bowel obstruction, retraction, necrosis,prolapse, stricture, fistula, and parastomal hernia. In some cases, suchas partial small bowel obstruction, the patient can first be treatedconservatively and surgical intervention may be avoided. Majorcomplications such as ostomy necrosis that extends more than a fewmillimeters, surgical intervention is mandatory. Minor complicationsinclude dermatitis, electrolyte imbalance, and dehydration from highostomy output, although the last often necessitates early closure of theostomy. For major complications, additional costs and morbidityassociated with additional operations or hospitalizations can besignificant. Even for minor complications, treating complications andproviding ostomy education can be burdensome to healthcare providers andpatients. Some complications such as hernia, prolapse, and stenosis maybecome chronic and often require multiple corrective operations andassociated costs. Ostomies also significantly reduce a patient's qualityof life. Fecal output from the ostomy is collected into an ostomy bagattached to the patient's abdomen. These bags need to be emptied andreplaced regularly to properly care for the ostomy and preventunintentional discharge of fecal material.

Furthermore, the reversal of an ostomy is a surgical procedure fraughtwith potential complications, as often times the abdominal compartmenthas dense adhesions that make re-establishment of normal bowelcontinuity both costly and potentially morbid. In addition to expensesassociated with taking patients to the operating room, patientstypically require a hospitalization of 2-4 days post-procedure to allowfor support until bowel function returns. Furthermore, the reversal ofan ostomy may be difficult or impossible in some patients, requiring thepatient to live the rest of their life with an ostomy. The repairedbowel after ostomy takedown may also develop a leak at the repair siteor anastomotic site in cases of loop ileostomies or in cases of endostomy reattachment, respectively.

Besides anastomotic protection, there are other potential indicationsfor temporary fecal diversion. These include: 1) treatment of ananastomotic leak after it has occurred, 2) diverticulitis, 3)inflammatory bowel diseases such as Crohn's or Ulcerative Colitis, 4)intestinal perforation and 5) other less common instances of bowelinjury where fecal diversion could be useful such as in cases ofischemic bowel disease, bowel contusion injury from trauma, ornon-healing perineal/perianal wounds. When a leak or bowel perforationhas occurred such as in cases of anastomotic leak and diverticulitis asexamples, treatment with fecal diversion can reduce the severity andextent of the condition. Thus, these patient may heal theirleak/perforation faster and not develop more severe complications whencontinued fecal flow contamination of the affected site is mitigated.Inflammatory conditions of the bowel wall such as Crohn's disease orUlcerative Colitis can make the intestinal lining susceptible to damagefrom fecal flow. Continued fecal flow can further inflame andcontaminate the bowel wall and lead to worsening of patient's overalldisease or even frank perforation of the bowel wall. Protection fromfecal flow allows the inflamed sections of bowel to rest and heal, andpotentially fecal diversion could reduce recovery time, hospitalizationtime, and limit severe complications such as perforations or fistulaformation. Patients with these conditions may not be good candidates forsurgery due to their concomitant conditions or sepsis; thus, performingmajor surgery to create an ostomy can be morbid in these cases.Accordingly, there is a need for improved method and devices to providea less morbid alternative for fecal diversion.

In the past, the concept of an intraluminal sheath for internal fecaldiversion has been described (U.S. Pat. Nos. 4,716,900; 4,905,693; U.S.Patent Application Publication No. 2010/0010519). The principalchallenge has been developing a device that can anchor securely withinthe bowel without harming the bowel wall itself and effectivelyaccomplishing air and fluid tight fecal flow diversion. Staple andsuture based techniques for devices such as those described by Ravo etal. (U.S. Pat. No. 4,716,900), Ravo (U.S. Pat. No. 4,905,693), andStopek et al. (U.S. Patent Application Publication No. 2010/0010519) areboth potentially harmful to the area of bowel damage from traction andcannot achieve effective sheath anchoring without major surgery. Othermethods of anchoring within the bowel have also been described thatdependent on scar formation to secure an anchor in place such as thedevice described by Baker (U.S. Patent Application Publication No.2008/0215076). This method however is not easily reversible and dependson the body's scar forming ability which may be compromised in somepatients for secure anchoring. There have also been stent-based anchorssuch as the devices described by Khosrovaninejad (U.S. PatentApplication Publication No. 2011/0295288), Levine et al. (U.S. Pat. No.7,267,694), Rockey (U.S. Pat. No. 4,641,653) and Bessler et al. (U.S.Pat. No. 7,211,114), but stents do not provide enough anchor strength tohold the sheath firmly in place during bowel peristalsis as evidenced bytheir high rate of premature expulsion, and may further damage the bowelwall due to the necessary rigidity and expansion force they exert toprovide anchoring. Others have attempted using a fixed biodegradablering anchor placed outside and around the bowel wall such as Assaf etal. (U.S. Patent Application Publication No. 2013/0158463), but thisapproaches also requires major surgery for placement and exposes thebowel to potential erosion and damage due to pressure points exerted onthe bowel wall. In addition, the necessity of creating a substantial airand fluid tight bypass of fecal contents has also been a technicalchallenge. Inflatable balloon types of seals such as those described byAssaf et al. (U.S. Patent Application Publication No. 2013/0158463) andWeig (U.S. Pat. No. 8,388,586 and U.S. Patent Application PublicationNo. 2010/0022976) have been described to try and achieve air and fluidtight seals within the intestines, but these again require potentiallyharmful expansible forces and pressure on the bowel wall to form a sealand often fail to achieve an adequate air and fluid tight barrier toenteric flow.

Negative pressure wound therapy has been used to treat anastomotic leaksin the past, and these dressings typically utilize a foam interface overthe damaged area of bowel covered by an occlusive barrier connected to anegative pressure source. Devices specifically designed to treat woundsand provide negative pressure treatment in the intestine or bodycavities have been described (U.S. Patent Application Publication No.2013/0190706, U.S. Pat. No. 8,926,576, and U.S. Patent ApplicationPublication No. 2015/0250979). Importantly, these devices are designedto be placed and to deliver negative pressure at the site of ananastomosis or tissue damage and as a result can cause further damage tothe area of the anastomosis or tissue damage when longitudinal forcesare placed on these devices or negative pressure ischemia is induced.These devices are not designed to protect the bowel lumen distal to thesite of placement. These types of dressing devices for negative pressurewound therapy have difficulty establishing and maintaining air tightseals and become frequently dislodged due to their lack of adequatesealing mechanisms. Furthermore, these devices are not configured in away to withstand the additional longitudinal forces that can displacethe device with the addition of a protective sheath. Lastly, thesedevices employ expandable wire-stent based designs to provide semi-rigidstructure (U.S. Patent Application Publication No. 2013/0190706, U.S.Pat. No. 8,926,576, and U.S. Patent Application Publication No.2015/0250979) that can create tissue damage and make them more prone toexpulsion from the bowel due to peristaltic forces. Khosrovaninejad(U.S. Patent Application Publication No. 2014/0222039) has used negativepressure suction to attempt to anchor a protective sleeve within thebowel. The major issues with this device are that the attachment andanchoring of the device is dependent on the adherence forces of negativepressure delivered via perforations and the radial expansion force of astent-based design. Perforations do not allow for adequate frictionforce to be generated to substantially fix a device in place and resistthe expulsion forces of the bowl. Thus, this device is designed to beexpulsed from the body after several days and must be placed very highabove an area to be treated. Furthermore, the expansile stent-baseddesign suffers from the same issues of other stent-based designs ofpotential bowel damage and expulsion. Accordingly, there needs to be adevice and method that can securely anchor within a body cavity in acontrolled fashion that has an improved safety profile and increasedanchoring strength and reliability.

SUMMARY

According to some embodiments of the invention, an anchoring systemincludes a sleeve having an inner surface defining a first lumen, afirst annular sealing mechanism disposed at a proximal end of thesleeve, and a second annular sealing mechanism disposed at a distal endof the sleeve. The anchoring system further includes a pressure tube influid connection with an outer surface of the sleeve, a sheath inmechanical connection with the sleeve, the sheath forming a secondlumen, the second lumen being in fluid connection with the first lumen,and open-cell foam disposed on the outer surface of the sleeve.Application of negative pressure to the pressure tube causes a seal toform between the first and second annular sealing mechanisms and aninner surface of a tissue cavity. Application of negative pressure tothe pressure tube also creates a frictional force that resistsdisplacement of the sleeve.

According to some embodiments of the invention, the application ofnegative pressure to the pressure tube brings the open-cell foamdisposed on the outer surface of the sleeve into contact with the innersurface of the tissue cavity thereby creating the frictional force thatresists displacement of the sleeve.

According to some embodiments of the invention, the first and secondannular sealing mechanisms form a substantially airtight and fluid-tightseal with the inner surface of the tissue cavity. According to someembodiments, the first and second sealing mechanisms comprise a roundedprotrusion or multiple protrusions placed in series at each end of thesleeve that are compressible. According to some embodiments, each of thefirst and second sealing mechanisms comprises a plurality of concentricfins that form a series of concentric seals. According to someembodiments, each of the first and second sealing mechanisms comprises aplurality of concentric protrusions that form a series of concentricseals.

According to some embodiments of the invention, the sheath protects theinner surface of the tissue cavity from fecal flow distal to the sleeve.According to some embodiments, the first lumen has a diameter betweenapproximately 1 cm and approximately 6 cm. According to someembodiments, the outer surface of the sleeve has a diameter betweenapproximately 1.1 cm and approximately 6.1 cm. According to someembodiments, the sleeve comprises a flexible material having a Shore Ahardness between about 20A and about 70A. According to some embodiments,the sleeve has a length that is between about 3 cm and about 25 cm.According to some embodiments, the sleeve has a tubular wall thicknessof between about 0.1 mm and about 8 mm. According to some embodiments,the sleeve has a tubular wall thickness that is between about 0.2 mm andabout 5 mm.

According to some embodiments of the invention, the open-cell foamcomprises a material having an average pore size between about 50microns and about 1000 microns. According to some embodiments, theopen-cell foam comprises a material having an average pore size betweenabout 300 microns and about 600 microns. According to some embodiments,the open-cell foam comprises a material having an average pore sizebetween about 100 microns and about 300 microns. According to someembodiments, the open-cell foam is compressible by peristalticcontractions of a patient's bowel. According to some embodiments, theopen-cell foam comprises polyvinyl alcohol, polyurethane foam, or othersynthetic polymer. According to some embodiments, the open-cell foam hasa tensile strength of at least 50 kpa. According to some embodiments,the open-cell foam has a thickness of between 2 mm and 150 mm. Accordingto some embodiments, the open-cell foam comprises a single tubular pieceof foam.

According to some embodiments of the invention, the first and secondannular sealing mechanisms comprise a flexible material having a Shore Ahardness between about 20A and about 70A. According to some embodiments,the first and second annular sealing mechanisms have an annular diameterthat is greater than an annular diameter of the open-cell foam dispersedaround the sleeve. According to some embodiments, the first and secondannular sealing mechanisms comprise one or more tapered fins placed inseries on each end of the sleeve with an orientation directed away froma center of the sleeve so that the one or more tapered fins lie flatagainst the inner surface of the tissue cavity when negative pressure isdelivered through the pressure tube. According to some embodiments, thefirst and second annular sealing mechanisms comprise a roundedprotrusion or multiple protrusions placed in series at each end of thesleeve that are compressible.

According to some embodiments of the invention, the anchoring systemfurther includes a negative pressure source, wherein negative pressureis applied to the pressure tube by the negative pressure source tomaintain constant negative pressure at a level between −50 mmHg and −200mmHg. According to some embodiments of the invention, the anchoringsystem further includes an irrigation tube in fluid connection with theouter surface of the sleeve. According to some embodiments of theinvention, the anchoring system further includes an irrigation system influid connection with the pressure tube, wherein the irrigation systemintroduces a fluid into the pressure tube for irrigation.

According to some embodiments of the invention, the sheath has a lengththat allows it to extend outside the tissue cavity. According to someembodiments, wherein the first lumen, second lumen, and first and secondannular sealing mechanisms are compressible by normal peristaltic forcesof a patient's bowel. According to some embodiments, a diameter of thefirst annular sealing mechanism and the second annular sealing mechanismis less than or equal to a diameter of the tissue cavity in which thesheath is to be anchored. According to some embodiments, the anchoringsystem is configured so that traction on the sheath can be used toremove the anchoring system from the body cavity. According to someembodiments, the sheath has a wall thickness that is between about 50microns and about 5 mm. According to some embodiments, the sheath has alength that is between about 8 inches and about 72 inches. According tosome embodiments, the sheath has markings along its length that indicatethe length of sheath within the tissue cavity after placement. Accordingto some embodiments, the sheath is comprised of silicone, polyurethane,thermoplastic elastomer, rubber, or other polymer.

According to some embodiments of the invention, the pressure tube isattached to the sheath along its length. According to some embodiments,the pressure tube is disposed within a wall of the sheath. According tosome embodiments, the pressure tube is integrated into the sheath andcomprises a same material as the sheath. According to some embodiments,the pressure tube is disposed within an additional lumen along thelength of the sheath.

According to some embodiments of the invention, the sleeve, first andsecond sealing mechanisms, and sheath are comprised of one or more ofsilicone, polyurethane, thermoplastic elastomer, rubber, rubber-likematerial, or other polymer.

According to some embodiments of the invention, the anchoring systemfurther includes a plurality of pressure tubes in fluid connection withthe outer surface of the sleeve.

According to some embodiments of the invention, the anchoring systemfurther includes an effluence bag in fluid connection with the sheath,the effluence bag configured to receive the content of the sheath.According to some embodiments, the effluence bag is detachable.

According to some embodiments of the invention, the sleeve, the firstannular sealing mechanism, and second annular form a first anchoringelement, and the anchoring system further includes a second anchoringelement in mechanical connection with the sheath, the second anchoringelement disposed apart from and distal to the first anchoring element,and a port disposed between the first anchoring element and the secondanchoring element. The sheath, the first anchoring element, and thesecond anchoring element create a sealed off space between the first andsecond anchoring elements, the sheath, and the inner surface of thetissue cavity, and the port is in communication with the sealed offspace to allow access from outside a patient's body for fluid deliveryand withdrawal. According to some embodiments, the sheath is dividedinto multiple anchoring segments having an independent negative pressuresupply. According to some embodiments, the fluid administered is ananti-inflammatory, chemotherapeutic, antimicrobial, radiologic contrast,or cleansing solution. According to some embodiments, the sleeve isdivided by additional sealing mechanisms to create multiple anchoringsegments. According to some embodiments, multiple pieces of foam aredispersed around each anchoring segment. According to some embodiments,each of the anchoring segments has an independent negative pressuresupply.

According to some embodiments of the invention, the sleeve and first andsecond annular sealing elements are made from a single injection moldusing a single material. According to some embodiments, the sheathcomprises a releasable, fluid-tight sheath connector at between 8 inchesand 36 inches from the second annular sealing mechanism. According tosome embodiments, the sheath comprises a separation junction at between8 inches and 36 inches from the second annular sealing mechanism.According to some embodiments, the anchoring system is configured to bepositioned in the tissue cavity using an endoscope. According to someembodiments, the anchoring system is configured to be attached to areleasable clip on an end of the endoscope that can release theanchoring system from the endoscope from outside a patient's body.According to some embodiments, the tissue cavity is bowel comprising ananastomosis, and wherein the anchoring system is positioned within thebowel such that the anastomosis is located distal in the bowel to thesecond annular sealing mechanism. According to some embodiments, theanchoring system further includes an irrigation system in fluidconnection with the pressure tube, wherein the irrigation systemintroduces a fluid into the pressure tube for irrigation.

According to some embodiments of the invention, a delivery systemincludes a flexible tubular membrane that encases the anchoring systemaccording to embodiments of the invention, and a semi-rigid tube pusherwith a proximal end, a distal end, and a center. The anchoring system isconfigured to be pushed into position by advancing the semi-rigid tubepusher into a patient's bowel, and the flexible tubular membraneinvaginates down the proximal end and out the distal end of thesemi-rigid tube pusher.

According to some embodiments of the invention, the delivery systemcompresses the anchoring system and holds the anchoring system to thesemi-rigid tube pusher when longitudinal traction is applied to theflexible tubular membrane. According to some embodiments, the deliverysystem further includes a flexible member that can be detached from asemi-rigid tube pusher and extracted from a patient's body through thecenter of the semi-rigid tube pusher after placement of the anchoringsystem.

According to some embodiments of the invention, a temporary anchoringdevice for diverting fecal flow through a bowel lumen includes a sleevehaving an inner surface defining a first lumen, a first annular sealingmechanism disposed at a proximal end of the sleeve, and a second annularsealing mechanism disposed at a distal end of the sleeve. The temporaryanchoring device further includes a pressure tube in fluid connectionwith an outer surface of the sleeve, a sheath in mechanical connectionwith the sleeve, the sheath forming a second lumen, the second lumenbeing in fluid connection with the first lumen, and air conducting roughsurface material disposed on the outer surface of the sleeve.Application of negative pressure to the pressure tube causes a seal toform between the first and second annular sealing mechanisms and aninner surface of the bowel lumen, and the application of negativepressure to the pressure tube creates a frictional force that resistsdisplacement of the sleeve.

According to some embodiments, the air conducting rough material is astacked mesh matrix, a honey-comb lattice of interconnected channelsoriented in a radial fashion around the sleeve, gauze, fabric, or athree-dimensional woven material.

According to some embodiments of the invention, a method for anchoring asheath in a tissue cavity, the sheath being in mechanical connectionwith a sleeve, the sleeve having an outer surface comprising foam forcontacting an inner wall of the tissue cavity, and a sealing mechanismfor isolating a portion of the tissue cavity adjacent to the sleeve froma remainder of the tissue cavity, includes inserting the sleeve in thetissue cavity. The method further includes applying a negative pressureto a region between an outer surface of the sleeve and an inner surfaceof the isolated portion of the tissue cavity to create a frictionalforce between the outer surface of the sleeve and the inner surface ofthe tissue cavity.

BRIEF DESCRIPTION OF THE DRAWINGS

Further objectives and advantages will become apparent from aconsideration of the description, drawings, and examples.

FIG. 1 is a schematic illustration of an anchoring system according tosome embodiments of the invention.

FIG. 2A illustrates a method for insertion of the anchoring system in atissue cavity with a flexible member and semi-rigid tube pusher.

FIG. 2B illustrates the anchoring system detached from the deliverysystem (flexible member and pushing member removed) and in the desiredposition.

FIG. 2C illustrates the anchoring system once negative pressure isapplied through the pressure tube with collapse of the bowel wall aroundthe sealing members and anchor sleeve.

FIG. 3A shows the outer circumference of the foam surrounding the sleevein a tissue cavity under normal pressure conditions.

FIG. 3B shows the foam and tissue when negative pressure is applied witharrows showing the relative normal force.

FIG. 3C shows an expandable stent in the bowel prior to deployment ofthe expansion mechanism.

FIG. 3D shows the stent in an expanded state, with arrows showing therelative normal force.

FIG. 4 shows data from pull-out strength testing of 38 mm and 33 mm indiameter configuration of the anchoring system at different levels ofnegative pressure.

FIG. 5 shows pullout force for different configurations and pressures.T-test demonstrated significantly (p=<0.05) higher pull-out force for a33 mm foam covered sleeve compared to a 33 mm sleeve without foam and a33 mm sleeve with negative pressure suction through perforations andwithout foam.

FIG. 6A shows an anchoring system according to some embodiments of theinvention anchored within the bowel when the bowel is at rest witharrows showing the relative normal forces exerted by the anchoringsystem and the bowel wall.

FIG. 6B shows the anchoring system during peristalsis with arrowsshowing the relative normal forces exerted by the anchoring system andthe bowel wall.

FIG. 6C shows a semi-rigid, stent-like device in a bowel at rest witharrows showing the relative normal forces exerted by the device and thebowel wall.

FIG. 6D shows the stent during peristalsis with arrows showing therelative normal forces exerted by the device and the bowel wall.

FIG. 7A shows a cross-section view of a first configuration of thesealing elements and sealing mechanisms.

FIG. 7B shows a cross-section view of a second configuration of thesealing elements and sealing mechanisms.

FIG. 7C shows a cross-section view of a third configuration of thesealing elements and sealing mechanisms.

FIG. 7D shows a cross-section view of a fourth configuration of thesealing elements and sealing mechanisms.

FIG. 7E shows a cross-section view of a fifth configuration of thesealing elements and sealing mechanisms.

FIG. 7F shows a cross-section view of a sixth configuration of thesealing elements and sealing mechanism.

FIG. 7G shows a cross-section view of a seventh configuration of thesealing elements and sealing mechanisms.

FIG. 7H shows a cross-section view of a eighth configuration of thesealing elements and sealing mechanisms.

FIG. 7I shows a cross-section view of a ninth configuration of thesealing elements and sealing mechanisms.

FIG. 7J shows a cross-section view of a tenth configuration of thesealing elements and sealing mechanisms.

FIG. 8 shows a cross section of the anchoring portion of the anchoringsystem with an alternative sealing element geometry.

FIG. 9 shows data demonstrating pullout strength with one, two, or threesealing elements per side of the sleeve at −75 mmHg of negativepressure. The embodiment with three sealing elements has a significantlyhigher pullout strength than that with one sealing element.

FIG. 10 shows data demonstrating pullout strength with one, two, orthree sealing elements per side of the sleeve at −150 mmHg of negativepressure. The embodiment with three sealing elements has a significantlyhigher pullout strength than that with one sealing element.

FIG. 11 illustrates an anchoring system according to some embodiments inwhich the sealing mechanisms have two sealing elements on each side ofthe sleeve that include concentric external protrusions that form aseries of concentric seals.

FIG. 12 illustrates an additional anchoring system according to someembodiments in which the sealing mechanisms have three sealing elementson each side of the sleeve that include concentric external fins thatform a series of concentric seals.

FIG. 13A illustrates a first configuration of the junction between thesleeve and the pressure tube according to some embodiments.

FIG. 13B illustrates a second configuration of the junction between thesleeve and the pressure tube according to some embodiments.

FIG. 13C illustrates a third configuration of the junction between thesleeve and the pressure tube according to some embodiments.

FIG. 14 shows a side cross-section view of an anchoring system accordingto some embodiments of the invention.

FIG. 15 shows a junction between the sleeve and the pressure tubeaccording to some embodiments.

FIG. 16 illustrates an anchoring system with a deployment devicedisposed in the lumen of the sleeve and sheath.

FIG. 17 shows a side view of the anchoring system within a deliverysystem that includes a flexible membrane and semi-rigid tube pusher.

FIG. 18 shows an embodiment of the anchoring system that includes twoanchor elements to deliver therapeutic agents to an isolated segment ofbowel.

FIG. 19 shows a side view of an embodiment of the anchoring system thatincludes two anchor elements to deliver therapeutic agents to anisolated segment of bowel.

DETAILED DESCRIPTION

Some embodiments of the current invention are discussed in detail below.In describing embodiments, specific terminology is employed for the sakeof clarity. However, the invention is not intended to be limited to thespecific terminology so selected. A person skilled in the relevant artwill recognize that other equivalent components can be employed andother methods developed without departing from the broad concepts of thecurrent invention. All references cited anywhere in this specification,including the Background and Detailed Description sections, areincorporated by reference as if each had been individually incorporated.

Disclosed herein are systems and methods for anchoring a protectivesheath within the bowel proximal to a region of bowel that requiresprotection from fecal flow, such as a bowel anastomosis or area of boweldamage. The system and methods can make temporary fecal diversion ostomysurgery unnecessary in most patients, as it provides internal fecaldiversion and accomplishes the same overall objective as a temporaryostomy by protecting the distal segment of bowel from fecal flow. Inaddition, we disclose additional configurations of this system thatenable drug delivery to the intestinal lumen.

The system includes an anchoring mechanism that allows for non-traumaticand reversible anchoring of a sheath within the GI tract that divertsfecal contents away from the anastomotic site or area of damaged bowel.The device is designed to be left in place for a period of a few days tofour weeks, and then removed completely from the patient after healinghas occurred or diversion is no longer required. While the device andmethod are described here in the context of securely anchoring a sleevewithin the GI tract for the purpose of therapeutic benefit such asdiverting bowel contents, the device and method for anchoring may alsohave applications in other regions of the body where secure anchoringwithin a tissue cavity is desired. It is important to emphasize thatthis is a device designed to be substantially and securely anchored inplace within the bowel and to prevent substantial device migration untilthe device is actively disengaged and removed by the clinician. This isin contrast to other non-surgically attached sheath based protectiondevices that are unable to be securely anchored and are slowly extrudedfrom the bowel over time because they cannot maintain the same highlevel of anchoring strength required to resist bowel expulsion forces.The unique design of the device disclosed herein allows for it to anchorin place within the bowel without dislodgement, without damaging thebowel wall, without the need for a surgical fixation such as suturing orstapling, and without the need for a permanent implant. Each of thesefeatures are described in more detail below.

According to some embodiments, the device includes a negative pressurebased anchoring system that prevents a sleeve from becoming dislodgedfrom the inner surface of the bowel. The sleeve is connected to a sheathand acts, in combination with the sheath, as a protective barrierbetween the GI tract and the GI contents flowing through the sleeve andsheath. According to some embodiments, the device includes a pneumaticsystem for applying negative pressure to the anchor system. The devicein some embodiments includes an external effluence bag to collect GIcontent that flows through the sleeve and sheath. However, an externaleffluence bag is not required for the device to function. In someembodiments, the device has a sheath that is open just external to theanal sphincter and feces can be passed through this opening. In thisembodiment, the anal sphincter constricts around the sheath and providessome continence and a collection bag is not required.

According to some embodiments, the anchoring portion of the device ispositioned in the GI tract on the proximal side of an anastomosis orproximal to the area of damaged bowel. The proximal side is the sidethat is “upstream” in terms of the flow of GI content through the GItract. This is in contrast to anastomosis or wound treatment systemsthat are configured to be applied directly to an anastomosis or woundsite. This device is configured to be anchored in healthy undamagedbowel. Constant negative pressure is maintained via a pneumaticinterface connected to the anchoring system and dispersed through anopen cell reticulated foam interface. Special sealing elements at theend of the sleeve create a negative pressure space between the outersurface of the sleeve containing the foam interface and the bowel wall.When negative pressure is applied, the pressure gradient acts throughthe foam to create adhesive and friction forces between the GI tract andthe anchoring system. These adhesive and friction forces created by thenegative pressure-sponge interface enable the anchoring system tomaintain a relatively fixed position in the bowel that is much greaterthan other non-surgically fixated sheath anchoring systems previouslydescribed. When a user is ready to remove the device, normal atmosphericpressure between the anchoring device and bowel can be reestablished,allowing the device to move through the GI tract with minimal friction.The device and method of fixation do not require suturing, stapling,biodegradable implants, or other invasive anchoring techniques, andcreate minimal trauma to the bowel. Thus, disclosed herein are a methodand device for securely fixing a sleeve within the bowel lumen in amanner that does not substantially damage the bowel wall, and thatallows fixation to be easily reversed for device removal.

In accordance with the features of the embodiments of the invention, thedevice for anchoring the sleeve within the bowel can be described ashaving a hollow body with multiple seals on each end and porous materialon the external surface of the hollow body such that upon application ofnegative pressure to the external surface of the hollow body, anadhesive force forms between the bowel wall and hollow body. A tube candeliver negative pressure to the sealing member. A protective sleeve canbe attached to the sealing member and a collection system can collectcontents which pass through the sealing member.

FIG. 1 shows a cross-sectional view of the anchor portion of theanchoring system according to some embodiments of the invention. Theanchoring system 100 includes a sleeve 102 having an inner surface 104defining a lumen 106. A first annular sealing mechanism 108 is disposedat a proximal end of the sleeve 102, and a second annular sealingmechanism 110 is disposed at a distal end of the sleeve 102. For thedevice, proximal is defined as the part of the device farthest fromwhere fecal matter exits the sheath (at an effluence bag, for example),and distal is defined as the part of the device that is closer to wherefecal matter exits the sheath during regular fecal flow. Thisorientation convention is used because this is the relationship of flowthrough the device (from proximal to distal) and matches the orientationof the device within the bowel. A pressure tube 112 is in fluidconnection with an outer surface 114 of the sleeve 102. A sheath 116 isin mechanical connection with the distal end of the sleeve 102, andforms a second lumen 118 that is in fluid connection with the firstlumen 106. Open-cell foam 120 is disposed on the outer surface 114 ofthe sleeve 102. The application of negative pressure to the pressuretube 112 causes a seal to form between the first and second annularsealing mechanisms 108, 110 and an inner surface of the tissue cavity,and creates a frictional force that resists displacement of the sleeve102.

FIGS. 2A-2C illustrate a method for insertion and anchoring of theanchoring system. The anchor portion of the anchoring system 200comprising the sleeve, sealing mechanisms 212, 214, and foam dispersedaround the sleeve is transmitted through the tissue cavity 202 to theanchoring site. In the case of an anastomosis, the device is deliveredto a position proximal to the anastomosis, such that the sleeve andsealing mechanisms are all proximal to the anastomosis. A semi-rigidtube pusher 203 is used to position the device in the appropriateposition. A flexible membrane 204 covers the device and providesflattening of the sealing mechanisms 212, 214 to reduce friction duringplacement. The flexible membrane 204 also further reduces friction bycovering the foam dispersed over the sleeve. The device may also bedelivered using an endoscope or other delivery system. Example deliverysystems are discussed in detail below.

Once the device is positioned at the desired location above the arearequiring isolation from fecal flow by the sheath 220, it is detachedfrom the delivery system, and the delivery system components includingthe semi-rigid tube pusher 203 and flexible membrane 204 are removedfrom the patient.

FIG. 2B illustrates the device 206 detached from the delivery system andin the desired position. FIG. 2C illustrates the device 208 oncenegative pressure is applied through the pressure tube 210. As air isremoved from the space between the anchoring mechanisms on the outersurface of the sleeve, the inner walls of the tissue cavity are drawntoward the sleeve. As shown in FIG. 2B, unlike an anchor depending onexpansion forces to provide fixation such as a stent, the device 206 canhave some or all of its components' external diameter smaller than theinner diameter of the closed off tissue cavity inner wall 215, 217 inwhich it is to be anchored. The sealing mechanisms 212, 214 create aseal with the wall of the tissue cavity at either end of the sleeve. Asshown in FIG. 2C, the sealing mechanisms 212, 214 comprise sealingelements 222, 224 that are structured to conform to the inner walls 216,218 of the tissue cavity as negative pressure is applied, therebycreating a liquid-tight and air-tight seal. The flexibility of thesealing elements and the angle at which they protrude allows for them tofold down when negative pressure is applied to avoid creating pressureischemia of the bowel wall, as illustrated in FIG. 2C. This allows thesealing elements to lie flat against the tissue surface, creating a sealwith reduced pressure on the tissue at the interface between the sealingmechanisms 212, 214 and the tissue cavity wall 216, 218. Themultiplicity of the sealing mechanisms' annular design (i.e., havingmultiple circular fins or protrusions) allows for redundancy in the sealcreated and the ability to accommodate irregularities in the contour ofthe inner tissue cavity wall 216, 218. In addition, the sealing elementshave an external diameter that is greater than the external diameter ofthe foam. This allows for more reliable creation of a seal with thebowel when the bowel wall is sucked down during negative pressureactivation.

The seals at both ends of the sleeve prevent air from entering the spacebetween the sleeve and the cavity wall. The sealing mechanism 212 at theproximal end of the sleeve also diverts fluid and other GI contenttraveling through the tissue cavity into the central lumen of the sleevein cases where the tissue cavity is the bowel. The GI content passesthrough the central lumen and into the sheath 220. The GI content isthus isolated from the anastomosis more distal in the GI tract. Thisprevents anastomotic contamination with fecal flow. The sealing elementsin combination with negative pressure create an air and fluid tightbypass of GI contents that is superior to other methods such asinflatable cuffs that have been used in attempt to create an effectiveseal at the proximal end of an intraluminal bypass sheath.

FIGS. 3A-3D illustrate in cross-sectional view the forces applied to thetissue and anchoring system according to embodiments of the invention,and contrast these forces with those created by a device such as a stentthat relies on expansion to achieve fixation. FIG. 3A shows the outercircumference of the foam 300 surrounding the sleeve in a tissue cavity302 under normal pressure conditions. FIG. 3B shows the foam 304 andtissue 306 when negative pressure is applied. The application ofnegative pressure draws the tissue 306 toward the foam 304 until thetissue 306 and foam 304 are in contact. The foam 304 and remainder ofthe device are sufficiently pliable that the tissue 306 can compress thefoam 304 and remainder of device during normal peristalsis of the GItract. As shown in FIG. 2C, this can enable the tissue to contact thefoam along the full surface of the foam, from the proximal portion ofthe anchoring mechanism 212 to the distal portion of the anchoringmechanism 214. The contact between the tissue and the foam results in afriction force the resists displacement of the device. The negativepressure causes the bowel to be pulled toward the sleeve, minimizing thering tension applied to the tissue. This is important as expansileforces can create tissue stretching forces on the bowel wall that cancause stretch injury or decrease bowel wall perfusion. These issues areavoided using the device disclosed herein. The friction force isproportional to the normal force exerted on the device by the tissue andsurface area of the foam interface. For the device according to someembodiments of the invention, the normal force is primarily determinedby the negative pressure applied to the outer surface of the sleeve andthe friction force is determined by the surface area of the spongeinterface and characteristics of that sponge interface. These featureswill be described in more detail below.

In contrast, FIGS. 3C and 3D illustrate in cross-sectional view theforces for a stent-like anchoring device that relies on expansion tocreate friction. FIG. 3C shows the stent 308 in the bowel 310 prior todeployment of the expansion mechanism. FIG. 3D shows the stent 312 in anexpanded state. The normal force in this case depends on the size of thebowel in relation to the size of the stent, and on the bowel's springconstant. The stent-like anchoring device uses expansive forces whichare countered by the surrounding bowel. In order for the stent toachieve a similar normal force, and therefore a potentially similaranchoring force, as the device of the present invention, a highexpansive force is required that results in much higher tension withinthe ring of tissue. A stent-like anchoring device to anchor must have adiameter greater than the diameter of the tissue cavity treated.Accordingly, the device according to some embodiments of the inventionis capable of anchoring a sheath in the bowel with less stress andpotentially less damage to the bowel tissue. Because the bowel wall issucked down to the anchor using negative pressure in the discloseddevice, the exact bowel size is less important than if the anchoringforce depended on expansion forces employed by a stent or otherexpandable anchor types. Furthermore, the anchoring system can anchor ina tissue cavity at rest having a diameter that is greater than or equalto the diameter of the anchoring system. However, the anchoring systemcan also anchor in a tissue cavity having a diameter that is less thanthe diameter of the annular sealing mechanisms and/or the foam if thetissue cavity is stretchable.

FIG. 4 shows the pullout force as a function of negative pressure fordevices according some embodiments of the invention. The pullout forceis the force required to dislodge the device from a static state whennegative pressure is being applied. For the purposes of this disclosure,this occurs when traction forces that mimic expulsion forces of thebowel are great enough to disrupt the sealing elements resulting in lossof anchoring or displacement of the device >1 cm down the length ofbowel. FIG. 4 shows data for a device having annular sealing mechanismswith a 33 mm cross-sectional diameter, and a device having annularsealing mechanisms with a 38 mm cross sectional diameter.

The data in FIG. 4 demonstrate that with reduced diameter of the anchorportion of the device and associated reduced foam surface area there issome loss of anchoring strength. However, even with a much smallerdiameter device, unlike a stent device that relies on expansion forcefor anchoring, a smaller diameter anchor still maintains high anchoringforces in the same size bowel lumen.

The pullout force is directly proportional to the pressure leveldelivered to the device and surface area of foam in contact with thebowel wall. Higher pressure will result in a higher normal force andresultant higher friction that resists pullout of device. The data inFIG. 4 demonstrate that large forces (>5 lbs) are required to dislodgethe devices even when relatively small levels of negative pressure areapplied. Negative pressure levels less than −200 mmHg have been shown tobe safe to be used on human tissues, though perfusion is decreased atthe area where negative pressure is delivered with increasing levels ofnegative pressure. A benefit of the device described herein is that evenwith relatively low levels of negative pressures around −100 mmHg, theanchoring system still resists a significant pullout force due to thefriction created by the foam interface.

In addition, testing data demonstrates that even when the externaldiameter of the anchor device annular sealing mechanisms is in the rangeof about 50 percent the resting internal diameter of the bowel segment,anchoring can be effectively achieved. This is because when negativepressure is applied to the closed space of the intestine, the intestinecan be sucked down to the device diameter. The ability of the device toanchor due to its design after negative pressure is applied in a tissuecavity much larger than the external diameter of the device allows thedevice to be placed in a lumen easily and without the need forsubsequent expansion to achieve fixation within a cavity. A 65 mm indiameter segment of porcine intestine was used in benchtop testingmodel, and high levels (>5 lbs) of pullout strength was achieved with a33 mm in diameter anchor at −75 mmHg and −150 mmHg. These datademonstrated an average pullout strength similar to smaller sizes ofintestine tested with an average of 6.38 lbs and 12.62 lbs of forcerequired for displacement for −75 mmHg and −150 mmHg of negativepressure, respectively. These data demonstrate that the bowel sucks downto the size of the anchor and the sealing elements form a seal even whenthe bowel is much larger in diameter than the anchor body. This isimportant as it allows for a small in external diameter anchor elementto be placed into a segment of bowel without the need for expansion oncethe anchor element is positioned proximally within the bowel. The anchorelement includes the sleeve, the annular sealing mechanisms on eitherside of the sleeve, the open-cell foam, and the pressure tube. This alsoallows for simplified delivery through an intestinal narrowing such as astapled anastomosis which is typically significantly smaller than thenatural resting bowel diameter. The device eliminates the need for anexpansion mechanism such as a wire metal stent to achieve delivery ofthe device within a body cavity because a smaller in diameter device canbe delivered through the bowel and still achieve the same or higheranchoring force. With the foam interface, the forces on the bowel aredistributed across the entire contact surface area of the open-cell foam120, further reducing the device's potential to damage the bowel.

FIG. 5 shows the pull-out force required to dislodge devices havingthree different configurations at various pressures. The threeconfigurations include a sleeve with no foam, a sleeve with perforationsand no foam, and a sleeve with foam. The configurations without a foaminterface and with only perforations had significantly lower pull outstrength (adhesion) compared to when the foam interface was utilized, asshown in FIG. 5. This is because the foam provides a uniquely large highfriction surface area for the normal forces that result from negativepressure. These data are discussed in more detail below. Thus, having afoam interface or foam-like interface as part of the anchor device is animportant element of the disclosed invention. Without open-cell foam,the device would not have the ability to anchor securely within thebowel lumen. For example, as tested and shown in FIG. 5, having aplurality of perforations or holes does not provide nearly the sameanchor strength as foam. Furthermore, perforations or holes without afoam interface can suck tissue into the perforations or holes and resultin areas of pressure injury, ischemia, and tissue damage. Because foamdistributes pressure evenly over a large surface area, it prevents thistype of injury from occurring.

The anchoring system can be configured to have a series of anchoringconfigurations. In some embodiments, there is a single anchor elementthat includes the sleeve, a sealing mechanism on either side of thesleeve, foam, and pressure tubing. In other embodiments, the sheath maybe anchored by a plurality of anchor elements. Besides increasing theanchoring strength, having two anchor elements is important for anotherembodiment of the device. FIGS. 18 and 19 show an anchoring system fortreatment of the bowel wall. In this embodiment, the anchoring system1800 has a first anchor element 1801 at the proximal end of the systemthat is placed proximally in the bowel to an area of bowel to betreated, and a second more distal anchor element 1802 that sealsdistally in the bowel beyond the area to be treated. There is a port1809 in fluid communication with the sealed off space between the twoanchor elements and between the bowel wall and external surface of thesheath where fluid can be introduced or removed. A fluid tubing 1803 incommunication with the port 1809 can be used to introduce fluid from afluid infiltration source 1805 such as a syringe. This port can beaccessed from outside the patient's body via the fluid tubing 1803. Thisconfiguration of the device allows for delivery and removal ofirrigation, drugs (such as antibiotics, anti-inflammatory drugs, orchemotherapy agents), and radiologic contrast between the externalsurface of the sheath 1811 and bowel wall between the two anchorelements 1801, 1802. In some embodiments, the second, more distal anchorelement 1802 is shorter than the first more proximal anchor element1801, since the anchoring force of the second anchor element does notneed to be as strong and treatment near the anal verge may be requiredwhere a longer anchor element 1802 would not fit in the bowel. Thesystem 1800 further includes a pressure tube 1812. The pressure tube1812 can be in fluid connection with an outer surface of the sleeve ofthe first anchor element 1801 and the sleeve of the second anchorelement 1802, as shown in FIG. 18. Alternatively, the system 1800 mayinclude two pressure tubes, one for each of the first anchor element1801 and the sleeve of the second anchor element 1802. The pressure tube1812 is connected to a pneumatic system 1807 that is configured to applynegative pressure to the pressure tube to anchor the anchor elements1801, 1802.

FIG. 19 is a side view of an embodiment of the double anchor elementsystem, where like reference numerals as in FIG. 18 identify likefeatures. This configuration is clinically important for a number ofscenarios where treatment of an isolated segment of bowel could bebeneficial. Because this configuration allows for controlled containmentof a treatment agent within the bowel lumen for a discreet segment ofbowel, this embodiment provides a unique ability to provide sustainedand localized treatment of the bowel wall. For example, after endoscopicpolypectomy, the excision site could be isolated with the disclosedembodiment and be treated with local chemotherapy. Another example mightbe inflammatory bowel disease, where an affected segment of bowel couldhave anti-inflammatory agents delivered and maintained at the site ofdisease. In cases of bowel wall damage or perforation, antimicrobialagents could be introduced to decrease bacterial load during healing andmitigate the risk of worsening infection. The two anchor elements can bespaced anywhere from about 1 cm to 6 feet depending on the indicationand desired length of bowel to be treated. In some cases, the surgeonduring and open case can advance the device manually from the outside ofthe bowel wall, so a very long segment of bowel could be treated and theupper limit is the length of the entire bowel. This applies to the oneanchor element version of the device as well, as the device couldpotentially have a sheath length that could protect the entire bowel.

There are several key distinctions of this bowel protection device fromnegative pressure wound therapy treatment devices that may be usedwithin the intestine. The disclosed anchoring portion of the device isnot configured to treat an area of bowel injury, wound, or anastomosisdirectly. It is configured for anchoring a sheath portion of the devicethat protects the area of bowel injury, wound, or anastomosis.Importantly, the anchor portion of the device is designed to bepositioned in healthy uninjured bowel above or proximal in the bowelfrom the area of bowel injury. This method dramatically increases thepotential safety of this device as negative pressure is not delivered tothe area of the anastomosis, damage or injury; thus, the protected areaof bowel is never made ischemic or exposed to significant shear ortraction forces from the device.

Negative pressure when delivered through a sponge interface to tissueshas been shown to reduce the blood flow to areas where it is delivered.Thus, delivering negative pressure to the damaged area of the bowelitself can further damage the bowel or prevent healing as the bloodsupply of the bowel is less robust than for other tissues (especially atan area of anastomosis). Furthermore, the method and device describedhas a flexible sheath that covers the area of bowel anastomosis ordamage; thus, the anchoring of the device is in a separate location thanthe area of damaged tissue. During bowel contraction at the area ofdamaged bowel, there are less mechanical forces exerted on the bowelwhen it constricts around the device because the flexible sheath is lessmechanically rigid than a negative pressure wound therapy dressing thatemploy wire-stent based internal structures to maintain luminal patencyand facilitate anchoring. In addition, by placing the anchor far awayfrom the area of damaged bowel, the device does not exert mechanicalforce on the anastomosis or damaged tissue with traction or pulling onthe device from the pressure tubing or other portions of the device thatare external to the patient's body. No portion of the device is anchoreddistally to the damaged bowel; thus traction is only exerted on theproximal healthy bowel tissues. This further diminishes the risk ofpulling apart an anastomosis repair or injuring further an area ofdamaged bowel.

Another difference is that the anchoring device described herein musthave a much higher pullout strength as it must anchor strongly enough tomaintain the entire sheath and anchor element in position in normallyfunctioning, uninjured bowel. To accomplish this, the body has to bemade long enough and wide enough to allow for adequate surface area ofsponge contact to prevent expulsion, the anchor and sheath must beconfigured to conform to resist displacement by peristalsis, and thesealing mechanism must be made more robust to prevent potential airleaks.

Unlike a device that is designed to be mechanically dislodged by bowelfunction and peristalsis over time, the described device is designed tostay in place over an extended period of time until it is removed by thetreating clinician. The higher anchoring strength of this anchoringsystem 100 and more solid fixation is important because it allows forplacement of the device near the site of bowel being treated. In casesof bowel anastomosis in the colon, placement of a device higher into thebowel from the anus becomes more challenging due to the curvature of thebowel. So unlike devices that must be placed much higher (>40 cm abovearea to be treated) in the bowel due to device migration during thetreatment period, the fixed anchoring provided by the disclosedanchoring system enables the anchoring element (sleeve, annular sealingmechanisms, and foam) to be placed only a couple of centimeters abovethe area to be treated. However, it may be preferable to have the anchorelement placed at least 10 cm above the area to be treated to avoidlocal ischemia.

This ability to deliver controlled anchoring is achieved through thedescribed design elements elaborated on below.

The components of the anchoring system according to some embodiments ofthe invention are described in detail below. Reference is made to FIG. 1unless indicated otherwise.

Sleeve

According to some embodiments of the invention, the sleeve 102 is aflexible, concentric tube. The outer diameter and profile can beconfigured to move within the bowel without significant resistance whennegative pressure is not being applied to the outer surface 114 of thesleeve 102. In some embodiments the external diameter of the sleeve isbetween 11 mm and 61 mm in cross-sectional external diameter. Theinternal diameter of the sleeve determines the diameter of the firstlumen, and in some embodiments, the sleeve has an internal lumendiameter of between 10 mm and 60 mm in cross-sectional internaldiameter. For anchoring in other tissue cavities than bowel, theseparameters will differ based on the hollow viscus in which anchoring isto be achieved. In some embodiments, the sleeve may have a diameter thatis greater than or equal to the diameter of the tissue cavity. In someembodiments, the sleeve may have a diameter that is less than thediameter of the tissue cavity. In some embodiments, the sleeve may havea diameter that is less than 95% of the diameter of the tissue cavity.In some embodiments, the sleeve may have a diameter that is less than50% of the diameter of the tissue cavity. In some embodiments, thesleeve may have a diameter that is less than 25% of the diameter of thetissue cavity.

In some embodiments, the sleeve 102 is configured to be flexible enoughto be easily removed by pulling on the sheath 116 to slide the sleeve102 out through the bowel and anus, but rigid enough to hold aconcentric shape so that it forms a lumen 106 when negative pressure isapplied. This allows for easy placement and removal of the device 100.When negative pressure is applied to the outer surface 114 of the sleeve102, the sleeve 102 and foam 120 surrounding the sleeve 102 conform tothe contours of the GI tract.

The sleeve 102 is configured to be soft and pliable, and not to causeerosion into the bowel. The sleeve 102 has enough flexibility andcompliance to allow for the proximal and distal ends of the sleeve toconform to the bowel contours so that the foam to bowel wall contact canbe maintained during peristalsis and the annular sealing mechanisms 108,110 can create and maintain a seal, yet keep the concentric tubularshape of the internal lumen 106 patent so GI contents can pass through.According to some embodiments, the sleeve 102 comprises medical gradesilicone, polyurethane, thermoplastic elastomer, rubber, or otherpolymer exhibiting the flexibility and rigidity properties describedherein. The flexibility of the sleeve 102 allows it to safely anchor ina patient's body because the flexibility of the sleeve reduces pressurepoints created from bowel contraction forces. The sleeve 102 accordingto some embodiments has a Shore A hardness between about 20A and about70A to allow for maximum flexibility while maintaining a concentric formand patent lumen. The sleeve flexibility is also determined by the bodywall thickness. The sleeve 102 is thin walled, again allowing fordeformational forces to act upon it from bowel peristalsis. In someembodiments, the sleeve has a main body thickness of between 0.1 mm and8 mm. The thinness allows for more durable materials to be utilizedwhile continuing to accommodate peristaltic motion of the bowel wall.

The flexibility of the sleeve 102 allows the sleeve 102 to deform withthe bowel during peristaltic motion. Peristaltic motion moves contentswithin the bowel by sequentially compressing the proximal section ofbowel. FIG. 6A shows the anchoring system according to some embodimentsof the invention anchored to the bowel wall 607 when the bowel is atrest. FIG. 6B shows the anchoring system during peristalsis. Arrowsindicate the relative normal forces; larger arrows indicate largernormal forces and smaller arrows indicate smaller normal forces. Becausethe device is flexible it maintains a seal between the sealingmechanisms 608, 610, even with deformation by peristalsis or passage ofenteric matter. It maintains surface contact between the foam 600 andbowel wall 607, and the bowel is able to compress the device without thedevice exerting large and potentially damaging forces on the bowel wall607 in return. With constant negative pressure maintenance, the negativepressure between the sealing mechanisms 608, 610 creates nearer toconstant normal forces during peristalsis along the length of the anchorelement that prevents migration by maintaining the foam 600 to bowelwall 607 relationship. Accordingly, the device conforms and moves inconjunction with the bowel wall 607 because of the distribution of theadhesive forces over the entire surface of the sleeve covered by thefoam interface.

The flexibility allows the sleeve to maintain the position of the foam600 on the bowel wall 607 without creating shear forces between the foam600 and bowel wall 607 during bowel contractions. In cases of lessflexible bodies such as a stent-based anchor 612 in FIG. 6C and 6D, thebowel is stretched and pulled around the anchor body because the anchorbody cannot conform adequately to accommodate contractions occurring ator near the anchor body. These resultant shear forces disrupt theposition of the device and can result in device migration. When thebowel contracts, the flexible sleeve deforms with the forces exertedthrough the attached foam so the foam can more easily deform with thebowel wall instead of shearing off the bowel wall resulting in devicemigration.

Furthermore, for a more flexible anchoring element, the peristaltic wavehas less ability to push against the anchoring element due to theflexibility and conformity to the contraction. In cases of a more rigidand less conforming body such as a wire-based stent, the peristalticwave has the resistance of the less deformable body to push against,resulting in device displacement.

Moreover, the flexibility, compressibility, and compliance of thedisclosed device aids in placement and removal of the device through thecurvature of the bowel lumen. The flexibility allows delivery of thedevice higher up in the digestive tract as the bowel becomes moretortuous and curved and allows for easy removal. This flexibility alsoallows for a longer sleeve 102 that has a larger foam 120 surface areaand higher resultant anchoring strength to be manipulated into thebowel. This flexibility is also important for the anchoring system 100as the foam 120 itself has a higher friction co-efficient than that ofdevices without foam, as shown in FIG. 5, even when no negative pressureis being delivered as during device removal and placement.

FIG. 5C shows a semi-rigid, stent-like device 612 in a bowel at rest,and FIG. 5D shows the stent-like device 612 during peristalsis. Incontrast to the disclosed invention, the stent-like device 612 has arigidity that resists compression. This rigidity increases the normalforces on the stent and the bowel as the bowel compresses, and causesthe stent to slip along the surface of the bowel along with theperistaltic wave of normal bowel contraction. Some stent-based designsdo have some compressibility and flexibility, but it is much lower thanthat of the disclosed device. Because of the low durometer construction,thinness, compressibility, and conformability of the device sleeve 102according to some embodiments, the sleeve is much more resistant todisplacement by peristaltic activity. The flexibility of the sleeve 102and sealing mechanisms 608, 610 has the further advantage compared tomore rigid devices of being more easily maneuvered for placement withinthe bowel along the normal longitudinal curvature of the bowel lumen.Moreover, when the device is placed in a region of bowel withlongitudinal curvature, it is more easily able to conform to accommodatethis curvature to maintain foam 600 to bowel surface area contact whennegative pressure is applied and prevent pressure points that canpotentially damage the bowel wall 607. In addition, the elimination of awire-stent based structure greatly enhances manufacturability from bothan ease and expense perspective.

The sleeve length determines the length of the anchoring element, andthe length of the anchor portion of the device is also an importantcharacteristic of the device. The anchoring strength of the anchorportion of the device is directly dependent on the length of the sleeveand associated surface area of the foam in contact with the bowel wall.Just like the diameter affects the surface area of the foam contact, sotoo does the length of the device. Unlike a stent, negative pressuredressing, or sheath that is located distally in the colon near the analverge over an anastomotic site or area of damaged bowel that can besupported in place by the device rigidity and does not need to conformsignificantly to the bends of the intestine proximally in the bowel, theanchor portion of the system according to some embodiments isconstructed in a window of lengths from >3 cm to <25 cm in length. Ourtesting in the porcine model indicates that if the anchor device is lessthan 3 cm in length with a diameter of 33 mm, it will not have thesurface area to maintain a pull-out strength of >5 lbs and may besusceptible to loss of seal and low force device displacement (<5 lbsforce). Furthermore, if the anchor portion of the device is longer than25 cm in length, the device cannot easily be place around the anatomicbends of the intestine and positioned in the intended area of anchoringthat is above (proximal in the bowel) the level of the area of bowel tobe protected. For applications in other tissue cavities that requireless pull out strength, such as a duct or esophagus, for example, thedevice may be shorter that 3 cm in length. Further, the embodiments ofthe invention are not limited to a flexible sleeve, and a stent-likesleeve surrounded in foam may also be used.

Sealing Mechanisms

The device 100 includes annular sealing mechanisms 108, 110 disposed ateach end of the sleeve 102. The sealing mechanisms 108, 110 contact theinner surface of the tissue cavity in which the sleeve 102 is inserted.The sealing mechanisms 108, 110 serve at least two functions. First,they create the seals between the proximal and distal ends of theexternal surface of the sleeve 102 with the bowel wall to create thenegative pressure space where the foam 120 can suck down to the bowelwall and create anchoring forces. Second, the seals create a fluid- andair-tight seal with the inner surface of the tissue cavity at either endof the sleeve 102 when negative pressure is applied to the outer surface114 of the sleeve 102 that diverts GI content through the lumen 106 ofthe sleeve 102 and into the lumen 118 of the sheath 116 attached to thesleeve 102. The angle that the sealing mechanism's sealing elements areslanted minimizes the risk of fecal forward or back flow from causingdisruption of the seal as fecal flow is directed towards the centrallumen of the sleeve by the sealing element. In some embodiments, theangle of slant from perpendicular to the bowel wall is between 5 and 25degrees. In some embodiments, the angle of slant from perpendicular tothe bowel wall is 25 to 45 degrees. In some embodiments, the angle ofslant from perpendicular to the bowel wall is 45 to 85 degrees. In someembodiments, there is no slant and the angle of slant from perpendicularto the bowel wall is 0 degrees.

The exact height of each sealing mechanism 108, 110 is less importantthan the relationship of the sealing mechanisms to the external diameterof the foam 120 covering. The sealing mechanisms 108, 110 of the systemin some embodiments extend beyond the height of the foam 120 at rest sothat when negative pressure is applied and the bowel wall collapses, aseal can be formed easily between the sealing mechanisms 108, 110 andbowel wall without interference by the foam 120. Thus, the annulardiameter of the sealing elements is greater than the annular diameter ofthe foam dispersed on the body of the sleeve at rest when no negativepressure is applied. In some embodiments, the sealing mechanism 108, 110extends at least 1 mm beyond the height of the foam 120 at rest.

The sealing mechanisms 108, 110 are made of a soft and flexible materialthat allows them to conform to the surface of the bowel. This isimportant because the peristaltic forces of bowel contraction can causepotentially harmful pressure points without this flexibility. Forexample, the sealing mechanisms 108, 110 can comprise thermoplasticelastomer, silicone, polyurethane, rubber, or other rubber-likematerials or polymers. The Shore A hardness of the material can rangebetween about 20A and about 70A. Similar to the low durometer of thesleeve, the low durometer of the sealing mechanisms allows forcompression and conformation to the bowel lumen during the sealingprocess when negative pressure is applied and during bowel peristalsis.The conformability, flexibility, and compressibility of the sealingmechanisms 108, 110 in a similar fashion to the flexibility of thesleeve allow decreased displacement during peristalsis and easier deviceplacement and removal.

The sealing mechanisms 108, 110 can include a plurality of sealingelements that are also referred to as fins or protrusions. Protrusionshave a more rounded geometry and fins are have a more tapered geometry.Both protrusions and fins extend radially beyond the external diameterof the sleeve to form seals at each end of the sleeve. The sealingelements extend radially toward the inner surface of the tissue cavityto varying degrees. In some embodiments, the sealing elements extendbeyond the foam radially allowing for sealing to occur at the ends ofthe sleeve 102 without interference from the foam 120. The sealingmechanisms 108, 110 may have multiple diameters along their body. Eachsealing mechanism 108, 110 can be a single sealing element or dividedinto multiple sealing elements. A sealing element is a single annularair and fluid tight sealing protrusion. In the case of multiple sealingelements, the sealing mechanisms can be configured to conform to the GItissue to create multiple local air and fluid tight seals. Some of thedifferent sealing mechanism and sealing element embodiments are shown inFIGS. 1, 7A-7J, 8, 11, 12, and 14-16. According to some embodiments, thesealing mechanisms 108, 110 may be oriented in different directions andshapes to create specific surface areas where negative pressure isapplied such as might be required for sealing in a hollow viscus otherthan the bowel with different anatomic geometry.

FIG. 7 shows some different configurations of sealing mechanisms andsealing elements in cross-section with only the upper half shown. FIG.7A shows three sealing elements in series that are concentricprotuberances oriented perpendicular to the sleeve. FIG. 7B shows threesealing elements in series that are concentric curved fins orientedperpendicular to the sleeve. FIG. 7C shows three sealing elements inseries that are concentric protuberances oriented at about 25 degreesfrom perpendicular. FIG. 7D shows three sealing elements in series thatare concentric curved fins oriented at about 25 degrees fromperpendicular. FIG. 7E shows three sealing elements in series that areconcentric protuberances oriented at about 45 degrees from perpendicularto the sleeve. FIG. 7F shows three sealing elements in series that areconcentric curved fins oriented at about 45 degrees from perpendicularto the sleeve. FIG. 7G shows three sealing elements in series that arewider based concentric protuberances oriented perpendicular to thesleeve. FIG. 7H shows six sealing elements in series that areconcentric, straight, and thin fins with a perpendicular orientation.FIG. 7I shows a single concentric curved fin sealing element that isoriented at about 45 degrees from perpendicular to the sleeve. FIG. 7Jshows two sealing elements in series with concentric, straight, and thinfins oriented at about 60 degrees from perpendicular to the sleeve.According to some embodiments, the sealing elements have a contoured andtapered shape that becomes thinner as the distance from the sleeve 102increases. These tapered fin shaped sealing elements as shown in FIGS.7B, 7D, 7H, 7I, 7J, have several advantages. They reduce the stiffnessof the outer portion of the sealing elements, thus reducing thepossibility of bowel wall damage when negative pressure is applied. Thecombination of the low durometer material and thin tapered design allowsfor very little pressure to be placed on the bowel wall when negativepressure is activated. Also, the low durometer and thin tapered designallow for maximum flexibility to allow for conformation during bowelperistalsis. This helps to maintain the seal during deforming forces ofbowel contraction and resists device expulsion. In some embodiments, thefins fold over to further mitigate bowel wall pressure points. Thecurved (FIGS. 7B, 7D, 7F and 7I), angled geometry (FIGS. 7C, 7D, 7E, 7F,7I, and 7J), and asymmetrical triangular shape (7H) all help inorienting the sealing elements to fold in a direction away from thecentral portion of the sleeve 102 during negative pressure delivery andbowel wall compression. The sealing elements shown in FIGS. 7A-7J arenon-limiting examples, and the embodiments of the invention are notlimited to these configurations. Further, the sealing mechanisms mayinclude two or more different types of sealing elements in a singlesealing mechanism. Each sealing mechanism may have one or more sealingelements.

FIG. 8 shows an anchoring system 800 according to some embodiments ofthe invention, where like reference numerals as in FIG. 1 identify likefeatures. The anchoring system 800 has sealing mechanisms 808, 810having a plurality of fins 822, 824 according to some embodiments of theinvention. Although the depicted fins 822 and 824 have angulations,angulation of the fins is not required if the fins are constructed of asoft enough material to conform to the bowel wall without significantpressure, but angulation of the fins can be beneficial. The angulationfrom perpendicular of the fins as shown in FIG. 8 is less than that ofthe fin embodiment shown in FIG. 1. Force of the bowel on the fins 822,824 causes them to conform to the shape of the bowel. This establishes aseal with the surface of the bowel at each end of the sleeve 802,creating a vacuum chamber. The sealing elements conform to the walls ofthe tissue cavity, and reduce the pressure on any single point in thetissue cavity. Instead, the pressure is distributed over the length ofthe sealing element. The seals that create the vacuum chamber alsoprevent enteric material from flowing around the outside of the sleeve802. The leading edge of the sealing mechanisms 808, 810 direct fluidinto the lumen 806 of the sleeve 802 as the outer surface 814 of thesleeve 802 and the inner surface of the tissue cavity are brought closertogether. In some embodiments, the sealing elements overlap, furtherreducing pressure points when sucked down to the bowel wall.

The sealing mechanisms according to some embodiments each have aplurality of sealing elements that are utilized at the ends of theanchoring portion of the device. These sealing elements createindividual seals and provide redundancy of seals that increases theforce required to displace the anchor when negative pressure isdelivered between the seals. When traction or physiological intestinalexpulsive force is placed on the anchor, the airtight seal formedbetween the device and the intestinal wall can be disrupted. When thisoccurs, the normal force and associated friction generated by thenegative pressure suction is dissipated, resulting in decreasedanchoring strength of the device. Having more than one seal has theadvantage of providing redundancy when disruptive contractile(squeezing) peristaltic forces of the bowel, displacing forces frombowel contents, or traction forces are placed on the device.

We further demonstrated this using our pullout strength testing in acadaveric porcine intestine model. The 33 mm anchoring device with foamwas fashioned with one, two, or three sealing elements per sealingmechanism 108, 110 on each side of the sleeve. Pullout strength wasmeasured by taking the force required to be placed on the device toachieve 1 cm of displacement (which was always accompanied by the lossof the suction seal) at −75 mmHg or −150 mmHg of negative pressure.FIGS. 9 and 10 show the pullout required for −75 mmHg of negativepressure and −150 mmHg of negative pressure, respectively. Pulloutstrength data for both levels of −75 mmHg and −150 mmHg of negativepressure demonstrated significantly (p-value≤0.05) higher pulloutstrength with three sealing elements versus one sealing element(p-value=0.0480 and p-value=0.0386). For example, for −75 mmHg ofnegative pressure, the force required to dislodge the device with onesealing element averaged 6.49 lbs, while the force required to dislodgethe device with three sealing element averaged 8.38 lbs. For −150 mmHgof negative pressure, the force required to dislodge the device with onesealing element averaged 9.73 lbs, while the force required to dislodgethe device with three sealing mechanisms averaged 15.21 lbs. These dataprovide support for the increased functionality of having multiplesealing elements (more than one per sealing mechanism) in a suctionbased intestinal anchoring system such as the one described here.

FIGS. 11 and 12 illustrate some additional embodiments in which thesealing mechanisms are configured as concentric sealing elements thatform a series of concentric seals. FIGS. 11 and 12 show anchoringsystems 1100, 1200 according to some embodiments of the invention, wherelike reference numerals as in FIG. 8 identify like features. The sealingelements 1122, 1124, 1222, 1224 of these systems are configured toprovide a series of seals to maintain a tight seal to the bowel even inthe event of small amounts of leakage of air at a single seal. Thesealing elements are configured to have a height and stiffness forforming an effective seal without causing pressure necrosis or erosionof the bowel wall as discussed above. In some embodiments, the pluralityof sealing elements lay flat when sucked down to the bowel wall so as tonot cause additional pressure points. This allows for significantpressure on the bowel only from the sealing elements activelymaintaining the negative pressure seal. The embodiment shown in FIG. 11is an embodiment that is configured with sealing elements 1122, 1124 asprotrusions with rounded ends that have a small amount of angulationfrom perpendicular. The embodiment shown in FIG. 12 shows a device withsealing elements 1222, 1224 configured as thin-edged fins having moreangulation from perpendicular than the sealing elements 1122, 1124 inFIG. 11.

The sealing mechanisms may be configured to be concentrically attachedaround the outer surface 114 of the sleeve 102 or may be integrated intothe wall thickness of the sleeve 102. Specifically, this relates to themanufacturing process used to create the anchor, as the sealing elementsmay be made in one mold with the sleeve or they may be separately moldedand adhered to the sleeve. According to some embodiments, the sealingelements and sleeve are created as a single molded part as both elementsof the device have similar material property requirements of strength,flexibility, and conformability. In some embodiments, the sleeve 102 andsealing mechanism 108, 110 are made from a single mold using the samematerial.

In some embodiments, the sleeve is divided into multiple anchoringsegments having an independent negative pressure supply. An anchoringsegment is a section along the sleeve that independently anchors thesleeve. In one embodiment, the sleeve is divided by one or moreadditional sealing elements to create two or more sealed off areas alongthe sleeve that independently anchor to the bowel wall. Foam is placedbetween each sealed off section to distribute pressure and interfacewith the bowel wall. Negative pressure is applied to the spaces betweenthe seals to create redundant areas of anchoring along the length of thesleeve. In some configurations, negative pressure is applied to eachsegment from independent negative pressure sources. In someconfigurations, the segments share the same negative pressure source.This embodiment, similar to having multiple anchoring elements, providesredundancy in the anchoring system. The advantage of this design is thatif the seal is broken in one segment, there are still adhesive forces atanother segment or segments.

Sheath and Collection Bag

The device 100 includes a sheath 116 that is in mechanical connectionwith the distal end of the sleeve 102. According to some embodiments,the sheath 116 is directly connected to the sleeve 102. According tosome embodiments, the sheath 116 is indirectly connected to the sleeve102. For example, the sheath 116 may be connected to the sealingmechanism 110 at the distal end of the sleeve 102. The sheath 116 formsa second lumen 118 that is in fluid connection with the first lumen 106.The sealing mechanisms 108, 110 divert GI content into the sleeve 102.When the GI content reaches the distal end of the sleeve 102 it entersthe lumen 118 of the sheath 116. The sheath 116 can have a length thatis sufficient to extend from the distal end of the sleeve 102 to apatient's anal canal, and outside the patient's body. Thus, once the GIcontent enters the sleeve 102, it is directed into the sheath 116, andis completely isolated from the inner surface of the patent's boweldistal to the sleeve 102. The sheath forms a barrier between the GIfecal flow content and the bowel wall, thereby protecting this portionof bowel. To isolate the bowel wall from fecal flow content, the sheathshould be substantially fluid impermeable. Secondarily, the sheath alsomechanically shields the bowel wall from mechanical expansion forces ofGI flow contents.

According to some embodiments, the sheath 116 is bonded to the sleeve102 or the distal sealing mechanism 110. The sheath 116 can have moldedfixation attachments that are configured to lock into the sleeve 102 orthe distal sealing mechanism 110. According to some embodiments, thesheath 116 is made of non-degradable biocompatible materials. Forexample, the sheath 116 can be made of silicone, polyurethane,thermoplastic elastomer, rubber, or other polymer, though theembodiments of the invention are not limited to these materials. Thesheath should be substantially impermeable to fluid and bacteria.

The sheath 116 is configured so that its diameter allows it to dwellwithin the GI tract without obstructing the flow of GI flow materialthrough it. In some embodiments, the sleeve has a cross-sectionaldiameter of between about 10 mm and about 60 mm. The sheath is made ofan appropriate material and is thin and compliant enough so that thesheath is compressible by the bowel wall and does not eliminate theeffects of peristaltic motion on fecal flow. Unlike a semi-rigiddrainage tube designed primarily to maintain patency and depend ongravity and gastrointestinal flow pressures for movement of GI contentsdown the tube, the sheath according to some embodiments is deformableduring peristalsis to allow for serial compressions to move GI contentsdown the sheath. This allows for placement of the device more proximallyin the bowel, as gravity and GI flow pressure is inadequate to movematerial through a longer length of tubing because resistance to flowincreases with tubing length. Furthermore, this compliance andassociated flexibility allows for navigation around bowel curvatures,improves patient comfort, decreases the chance of bowel walldamage/erosion, and prevents sheath clogging. Some embodiments of thesheath 116 have a wall thickness of between about 50 microns and 5 mm.In some embodiments, the length of the sheath 116 is sufficient for itto extend beyond the GI tract out of the anal canal after deviceplacement. In some embodiments, the sheath 116 is between about 8 inchesand 72 inches in length. In some embodiments, the device is configuredso that traction on the sheath 116 from outside the body can be used toremove the device from the body cavity. The sheath 116 must be strongenough to withstand longitudinal traction force without tearing of atleast 10 lbs of force so that the sheath can be used to extract thesleeve after treatment is completed. The sheath 116 in some embodimentsis marked with indicators along its length that show the length ofsheath 116 residing inside of the GI tract or tissue cavity afterplacement in bowel or other tissue cavity. A user can use the indicatorsto determine whether the sleeve 102 is migrating. The sheath 116according to some embodiments has a fixed length. According to someembodiments, the length of the sheath 116 can be adjusted by cutting thesheath 116.

According to some embodiments of the invention, a collection bag isdisposed at the end of the sheath 116. The collection bag should besubstantially impermeable to air and fluid. The collection bag collectsGI content that flows through the sleeve 102 and the sheath 116. In someconfigurations, the sheath 116 ends in a port that can be kept closedfor continence and opened to be emptied. In other configurations, thesheath 116 is flexible enough to allow the anal sphincter to compressthe sleeve and provide continence. In this configuration a collectionbag may not be used. According to some embodiments, the collection bagcan be detached and replaced as needed. In some embodiments, thecollection bag can be configured with a sealing attachment that allowsfor cutting of the length of the sleeve and re-establishing a seal tothe bag. In some embodiments, the collection bag has markings such thatthe volume of effluence can be determined. In some embodiments, thecollection bag has a leg strap for attaching the collection bag to thepatient's body. In some embodiments, the collection bag can also containa port to prevent any excess buildup of gasses. According to someembodiments, the external collection bag contains a one-way valve thatprevents collected GI contents from flowing back into the sheath. Insome embodiments, the collection bag has elastic leg straps that fastenthe collection bag to the patient's body.

Foam

The device 100 includes foam 120 that is disposed on the outer surface114 of the sleeve 102. The foam 120 or foam-like material serves acritical role in both increasing anchoring strength and preventingdamage to the bowel. The foam 120 provides a critical friction force tohold the sleeve 102 in place when suction is applied to the outersurface 114 of the sleeve 102. In addition, the foam 120 distributesnegative pressure and forces to minimize pressure points that mightdamage the bowel.

The foam 120 dispersed on the sleeve provides a high frictioncoefficient material with a maximum surface area where adhesion iscreated by the normal force created with negative pressure. Foam is theoptimal material for distributing negative pressure in this applicationand providing an effective coefficient of friction when negativepressure is applied. One could envision a device that uses a membranewith a series of holes placed in close proximity to form a porousmembrane to distribute negative pressure. However, the normal forcegenerated by a membrane based device is limited by the open surface areacreated by the holes. In addition, the porous membrane has a much lowercoefficient of friction than the rough surface of the foam. The foamalso has a larger surface area of effective contact with the bowel dueto its open cell structure and multiple pores for distributing negativepressure throughout its substance. To maintain a comparable pulloutstrength without foam, the magnitude of negative pressure required wouldhave to increase and place significant point stresses on the bowel. Thiswas demonstrated in a series of experiments performed in a cadavericporcine intestine model as shown in FIG. 5.

FIG. 5 shows the results of testing the anchor pull out strength for a33 mm diameter anchoring system 100 with various configurations. A 33 mmin diameter anchoring system 100 with foam 120 interface (the disclosedanchoring system), a 33 mm in diameter anchor device without foam 120interface (the disclosed anchoring system with foam removed), and a 33mm in diameter device with a plurality of perforations (a 33 mm indiameter anchor device with several dozen small 1-3 mm holes incommunication with a negative pressure source via tubing) were insertedinto porcine cadaveric intestine model and pullout force measurementswere taken with various amounts of negative pressure delivered to theanchor. Pullout was defined as the amount of force required to dislodgethe anchor with traction in the vector of the intestine. This force wasmeasured as the maximum amount of applied force before the device lostits seal or was displaced by 1 cm. When the pullout force is reached,there is a drop in the force required to pull the device out of theintestine as the suction seal is broken or disrupted which alsocorresponds to the device displacing in the intestine. Each conditionfor each experiment was repeated three separate times. Trials werecompleted using the same segment of cadaveric intestine for each anchor,though different segments of intestine with slightly different diameterwere used for repeat experiments. The data demonstrate that the anchorwith foam had 4.5 to 14 times higher pullout strength than the anchorwithout foam. The data further demonstrate that the anchor with foam hada 5.6 to 12.2 times higher pullout strength than an anchor with aplurality of small suction perforations/holes. These results weredramatic and statistical analysis (one-sided, non-equal variance t-test)for each pressure demonstrate significantly higher pullout strengths atall pressures tested for the foam anchor compared to either of thenon-foam anchors. The p-values demonstrating significant increasedanchoring strength with foam compared to the anchor with foam removedwere (175 mmHg) p-value=0.0012, (150 mmHg) p-value=0.0095, (125 mmHg)p-value=0.0079, (100 mmHg) p-value=0.0106, (75 mmHg) p-value=0.0034, (50mmHg) p-value=0.0017, and (0 mmHg) p-value=0.0010. The p-valuesdemonstrating significant increased anchoring strength with foam anchorcompared to the anchor with surface of multiple holes/perforations were(175 mmHg) p-value=0.0003, (150 mmHg) p-value=0.0071, (125 mmHg)p-value=0.0071, (100 mmHg) p-value=0.0112, (75 mmHg) p-value=0.0042, (50mmHg) p-value=0.0050, and (0 mmHg) p-value=0.0004. The anchor with foamremoved and anchor with multiple holes did not exhibit statisticallysignificant differences for pressure tested (all p-values>0.05). Asthese data demonstrate, the foam interface creates a significantincrease in pullout strength and anchoring force at a given negativepressure suction level that is not achievable without foam 120 orfoam-like substance. Even with multiple small perforations, pulloutstrength was only marginally increased when negative pressure wasapplied. In addition, with higher pressures, a multiplicity ofperforation/holes design for suctioning to the bowel can potentially bedangerous as the areas of tissue sucked up into the holes can becomeischemic as a continuous peripheral seal around each hole is necessary.In our cadaveric testing, we saw in the perforation model marking of theinternal surface of the bowel where tissue was sucked into the holes ofthe anchor even with short duration of treatment used in theseexperiments. In contrast, the foam interface showed no internal surfacemarking. The open-cell foam 120 distributes the negative pressure evenlyover the tissue better than individual holes or perforations and is muchless susceptible to damaging bowel tissue. Foam 120 provides adistribution of the negative pressure forces that is uniquely bothatraumatic to the intestinal tissues and creates high friction forcethat prevents the anchor from displacing.

The foam 120 comprises a material that is chosen to produce particularcompression characteristics and coefficients of friction to preventmigration of the sleeve 102. The foam 120 can comprise a material havinga pore size that allows negative pressure to be distributed throughoutthe foam, while preventing ingrowth of tissue into the foam. This allowsthe foam 120 to be easily dislodged from the inner surface of the tissuecavity when normal pressure is restored. In order to have thecharacteristics required to distribute negative pressure and create ahigh friction force, some embodiments of the foam 120 have an averagefoam pore size between about 50 microns to about 1000 microns indiameter. The average pore size of the foam in some embodiments isbetween about 100 and 300 microns. The average pore size of the foam 120in some embodiments is between about 300 and 600 microns. Too small apoor size and the foam 120 loses some of its friction ability and toolarge a pore size and the material may have tissue ingrowth and has alower tear strength. In some embodiments, the density and materialcomposition of the foam 120 must allow for an overall tensile strengthof the foam to be at least about 50 Kpa. This allows deforming forcesand traction on the sleeve to not shear or tear the foam. Because thefoam 120 is bearing the shear force exerted on the anchoring system 100the foam must have a high tear force that can withstand about 50 Kpa ofshear force and must be fixed to the sleeve 102 in a fashion that canwithstand about 50 Kpa of distraction force without separation. Thelevel of forces exerted on the device both from the peristaltic andexpulsive forces on the sleeve 102 and sheath 116 are much higher thanfor keeping in place a piece of foam to treat a small wound area asmight be done with negative pressure wound therapy.

The foam 120 in some embodiments is comprised of a material that ishydrophilic, which can prevent the foam from drying out the surfacetissue with which it comes into contact, though a hydrophobic materialcan also be used in some embodiments. According to some embodiments, thefoam 120 comprises polyvinyl alcohol. In some embodiments, the foam 120is made of polyurethane, another polymer, or organic fiber mesh. In someembodiments, the open-cell foam 120 comprises a single tubular piece offoam.

The foam 120 covers the outer surface 114 of the sleeve 102, and createsa friction force when negative pressure is applied to the outer surface114 that resists motion of the sleeve 102 with respect to the bowel. Theporosity of the foam 120 allows air to be evacuated from the regionbetween the outer surface 114 of the sleeve 102 and the inner surface ofthe tissue without strong suction being applied to any single point.This creates a frictional force that is evenly distributed across theouter surface of the foam 120. The foam 120 under negative pressure alsocreates a large surface area where frictional forces are created toresist dislodgement. The foam 120 is designed to be compressible tominimize the amount of force exerted on any single point of the bowelwhen negative pressure is applied, and to maximize the surface areacontact to the bowel wall by conforming to the shape of the bowel wall.

In some embodiments, the foam 120 dispersed over the sleeve must have athickness or height that allows for dispersion of negative pressurearound the sleeve but does not extend beyond the height of the radialedge of the sealing mechanisms at rest or results in narrowing of thesleeve lumen 106 to the point of obstructing GI content flow. If thefoam 120 is too thin, it will collapse or clog and not have enough openpores to evenly distribute negative pressure around the sleeve 102. Ifthe foam is too thick, it will prevent air tight seals from initiatingat the sealing mechanisms 108, 110 and constrict the diameter of thesleeve lumen 106. In some embodiments the thickness of the foam disposedaround the sleeve is between 2 mm and 1.5 cm.

According to some embodiments, the foam 120 can be segmented intoseparate subunits. In some embodiments, multiple pieces of foam aredispersed around each anchoring segment. As described above, thesesegments can be separated by multiple serial sealing elements. In theseembodiments, negative pressure can be applied to all of the subunits inparallel or separately through independent negative pressure supplies.

Alternatives to foam may be used in some embodiments of the disclosedinvention to form the interface with the bowel wall. These foam-likealternatives must distribute negative pressure evenly through thematerial, create a significant friction force to resist displacementwhen negative pressure is applied, have biocompatibility with thetissues of the GI tract, and compressibility and deformationalproperties that resist expulsion and pressure induced tissue damage.Some potential polymer-based alternatives are stacked mesh matrices thatare wrapped around the sleeve, a honey-comb lattice of interconnectedchannels oriented in a radial fashion around the sleeve, or 3-D wovensynthetic fabric material. Natural fiber alternatives include guaze,naturally occurring sponges, or woven fabric. However, some embodimentsof this device utilize open-cell reticulated foam.

Pneumatic System

The device 100 includes a pressure tube 112 that is in fluid connectionwith the outer surface 114 of the sleeve 102. The pressure tube 112 isconnected to a negative pressure source such as an air pump that sucksair out of the tube in a controlled fashion. This pump maintainsconstant negative pressure at a level of pressure that allows foradequate anchoring so that the sleeve does not become dislodged, butdoes not harm the bowel. The configuration of device allows forphysiologically safe pressures of up to −200 mmHg, though pressures of−50 to −150 mmHg may be the preferred range of negative pressuredelivery. When negative pressure is applied to the tube, a seal isformed by the sealing mechanisms 108, 110 at either end of the sleeve102. As the pressure tube 112 connected to a negative pressure sourcecontinues to apply negative pressure, the inner walls of the tissuecavity are pulled toward the outer surface 114 of the sleeve 102,bringing the tissue into contact with the sealing mechanisms 108, 110and the foam 120. The normal force created by the negative pressuresucking down the foam creates a friction force that resists motion ofthe sleeve 102. The pressure tube is configured to resist occlusion fromwall collapse when negative pressure is applied. In some embodiments,there are more than one pressure tubes to provide redundancy in case ofkinking or clogging of any one pressure tube. In some embodiments with aplurality of pressure tubes, more flexible and compliant tubing materialcan be utilized due to the redundancy of negative pressure delivery.Each of these pressure tubes are individually in fluid communicationwith the foam to allow for negative pressure delivery. In someembodiments, where there are multiple anchoring elements or in caseswhere there are multiple anchoring segments, there may be separatepressure tubes to each anchoring element or anchoring segment. Theplurality of pressure tubes can be connected to a single negativepressure source such as a single pump or individually to a plurality ofpressure sources such as multiple pumps.

The pressure tube 112 extends from the sleeve 102 beyond the anus. Thepressure tube 112 can be disposed within the wall of the sheath 116 orbe separate. According to some embodiments, the sheath 116 defines anadditional lumen in which the pressure tube 112 is disposed such that itis isolated from the GI content traveling through the sheath.Alternatively, the pressure tube 112 can be situated alongside thesheath 116, either attached to the outside of the sheath 116, inside thesheath 116, or detached from the sheath 116. In another embodiment, theadditional lumen in the sheath is the pressure tube.

The proximal end of the pressure tube 112 can be connect to the distalend of the sleeve 102 or to the annular sealing mechanism 110 disposedat the distal end of the sleeve 102. FIGS. 13A-13C illustrateconfigurations of the pressure tube 1324 and sleeve 1333 according tosome embodiments of the invention. The foam is not shown in FIG. 13A-13Cso that the relationship between the sleeve 1333 and the pressure tube1324 can be shown more clearly. In some embodiments, the outer surfaceof the sleeve 1133 including the openings in or to the pressure tubewill be covered in open-cell foam.

FIG. 13A shows an embodiment in which the sleeve has a tube-like feature1316 that protrudes from the distal end of the sleeve 1333 and is opento the outer surface 1320 of the sleeve 1333. The end of the tube-likefeature 1316 is sized to connect to the proximal end of the pressuretube. The two parts are bonded or welded together to create an air andfluid tight seal.

FIG. 13B illustrates an embodiment in which the pressure tube 1324 runsthrough a secondary lumen of the sheath 1322. A hole is punched throughthe side of the distal annular sealing mechanism 1310 or sleeve 1333,and the pressure tube 1324 is routed through to the outer surface of thesleeve under the foam (not shown). Multiple holes are punched into thepressure tube to create redundant pathways for negative pressuredelivery and to prevent clogging from disrupting negative pressuredelivery. A sealant/adhesive is used to bond the pressure tube to thesleeve, and to create an air tight seal around the pressure tube wherethe hole was punched in the annular sealing mechanism 1310 or sleeve1333.

FIG. 13C illustrates an embodiment where the pressure tube 1324 isrouted straight through the secondary lumen of the sheath 1322 and intothe inner lumen the sleeve 1333. According to some embodiments, thepressure tube 1324 extends to the proximal end of the sleeve 1333. Anadhesive may be applied to the pressure tube 1324 to hold it in placeagainst the inner surface of the sleeve 1333. The proximal end of thepressure tube 1324 is sealed. Holes are punched along the length of thesleeve 1333 through the sleeve and into the pressure tube 1324 to createcommunication between the outer surface of the sleeve 1333 and thepressure tube 1324 and negative pressure source. Foam (not shown) isdisposed on the outer surface of the sleeve 1333 so that the pressure isdistributed over the surface of the foam, instead of being concentratedat the holes in the sleeve 1333.

FIG. 14 shows a cross-sectional side view of an embodiment of theanchoring system 1400 corresponding to the device shown in FIG. 13A,where like reference numerals as in FIG. 1 and FIG. 8 identify likefeatures. The tube-like feature 1426 connects the pressure tubing 1412to the outer surface 1414 of the sleeve 1402 through an opening 1428.FIG. 15 shows a close-up view of the integration of the pressure tube1512 with the annular sealing mechanism 1524 and the sleeve 1502. Asdescribed above with reference to FIG. 13A, the sleeve has a tube-likefeature 1526 that protrudes from the distal end of the sleeve andconnects to an opening 1528 on the outer surface of the sleeve 1502. Thetube-like feature 1526 enables the pressure tube 1512 to be coupled tothe outer surface of the sleeve 1502 without disrupting the sealingfunction of the sealing mechanism 1524. The proximal end of thetube-like features is open so that negative pressure can be delivered tothe outer surface of the sleeve 1502 and foam (1420 in FIG. 14, notshown in FIG. 15).

FIG. 16 is a zoomed-out view of an anchoring system having the tube-likefeature shown in FIGS. 14 and 15. The anchoring system is shown with asemi-rigid tube pusher 1601 disposed in the lumen of the sleeve 1602 andsheath 1616. The tube-like feature 1628 is connected to the pressuretube 1612 that has an opening 1626 to the outside surface of the sleeve1602. Foam 1620 is dispersed around the sleeve 1620 between the proximaland distal annular sealing mechanisms 1622, 1624 and covers the opening1626 of the tube-like feature 1628.

According to some embodiments, the sleeve 102 and/or the second annularsealing member 110 has a nozzle connected to the pressure tube 112 incontinuity with the space occupied by the foam 120 that is configured tobe low profile and not impede flow through the lumen of the sleeve 102.According to some embodiments, the pneumatic interface contains aone-way valve that maintains the pressure gradient during momentary lossof negative pressure delivery from the pneumatic device. The one-wayvalve can be disposed in the tube-like junction shown in FIGS. 13A, 14,and 16, or in the interface between the pressure tube and the vacuumsource. According to some embodiments, an additional lumen in the sheath116 is the pressure tube 112, and ports connecting to the additionallumen may contain 1-way valves which are oriented to prevent the loss ofsuction. In some embodiments, these are one-way duck bill valves.

According to some embodiments, the pressure tube 112 is part of apneumatic system that controls the pressure on the outer surface 114 ofthe sleeve 102. The pneumatic system includes a pump that pulls air outof the pressure tube 112 and maintains near constant negative pressureat a set pressure level in the range of −50 mmHg to −200 mmHg. Thepneumatic pump may also in some configurations be capable of applyingpositive pressure, for example to assist in removal of the sleeve 102from the patient's bowel. The pneumatic pump can maintain negativepressure through an electric pump mechanism or mechanical pumpmechanism. The pneumatic system may include an indicator that allows theuser to determine whether sufficient negative pressure has been achievedand maintained. For example, the pressure gauge can be an indicator thatdemonstrates that sealing is maintained as suction force is measuredwithin the pneumatic system.

In some embodiments, the pressure tube 112 has an adaptor that can beused to attach a syringe so that the pressure tube can be flushed andthe foam 120 irrigated with fluid. This can be helpful with removal ofthe device from the bowel wall during the removal procedure or forflushing GI contents away from the foam interface that might clog thepneumatic system.

Insertion and Removal

During insertion into a patient's bowel, the device 100 is introducedinto the anal canal and moved past the anastomosis site, so that theannular sealing mechanism 110 disposed at the distal end of the sleeve102 is proximal to the anastomosis. The method of deployment depends onthe level of the anastomosis. For low anastomosis, the device can bedeployed through a capsule sheath system that is positioned manually.For higher anastomosis, an endoscope can be used to assist in thedeployment. The device can be placed over the outside of an endoscopeand affixed such that a user can position and deploy the device in thedesired location.

According to some embodiments, the anchoring system 100 is configured tobe placed into position by an endoscope. The device 100 can have asuture or tab present that can be grasped by an endoscope grasper topull the sleeve 102 in place using an endoscope. In some embodiments,the device is attached to a releasable clip on the end of the endoscopethat can release the device from the end of endoscope from outside thebody. Alternatively, an endoscope may be used to hold a flexible membersuch as a wire or string attached to the anchor that is looped out ofthe patient's body and pulled around the fixed end of the endoscopewithin the bowel to pull the device into the bowel and into the desiredposition.

In some embodiments, the sleeve 102 can be attached to the endoscopeusing a releasable from outside the body clamping mechanism. In someembodiments, the sleeve 102 can be attached to semi-rigid tubing thatfits over the endoscope. This tubing is configured to push the anchoringsystem 100 into place over the endoscope and then to release from theanchoring system 100. In other embodiments, the introducing member is afirst semi-rigid tube that contains the proximal portion of device. Thisfirst semi-rigid tube is advanced into the bowel through the anus, andafter reaching the desired position, a second semi-rigid pushing tubethat encircles the sheath and is smaller in diameter than the firstsemi-rigid tube is used to hold the device in place while the firstsemi-rigid tube is removed. The second semi-rigid pushing tube is thenremoved after negative pressure anchoring of the anchoring system 100 isinitiated.

As shown in FIG. 17, in some embodiments, the delivery system iscomprised of a flexible tubular membrane 1704 that wraps around theanchoring system and invaginates down a semi-rigid tube pusher 1703. Theflexible tubular membrane 1704 encases the anchoring system andinvaginates down the opening 1705 in the proximal end of the semi-rigidtube pusher 1703 and out the distal end of the semi-rigid tube pusher1703. In some embodiments, the end 1709 of the flexible tubular membrane1704 on the outside of the semi-rigid tube pusher 1703 is attached witha clamping mechanism 1714 to the semi-rigid tube pusher 1703. The end1711 of the flexible tubular membrane 1704 that exits out the distal endof the semi-rigid tube pusher 1703 in some embodiments is attached to ahandle 1707. Longitudinal traction in the distal direction on the handle1707 or the end 1711 of the flexible tubular membrane 1704 providescompression of the sealing elements 1708, 1710 and foam 1720.Alternatively, in some embodiments, the end of the flexible tubularmembrane 1704 that exits from within the distal end of the semi-rigidtube pusher 1703 is fixed to the end of the semi-rigid tube pusher 1703.Longitudinal traction in the distal direction on the flexible tubularmembrane end 1709 outside of the semi-rigid tube pusher 1703 providescompression of the sealing elements and foam to aid in delivery of thedevice. In these embodiments of the delivery system, the flexibletubular membrane 1704 also holds the semi-rigid tube pusher 1703 to theanchoring system, allowing the anchoring system to be advanced into thebowel with advancement of the semi-rigid tube pusher 1703. Since theflexible tubular membrane 1704 envelops the end of both the anchoringsystem and the semi-rigid tube pusher 1703, the anchoring system andsemi-rigid tube pusher 1703 are held together substantially enough whenlongitudinal traction is applied to the flexible membrane to allow foradvancement of the anchoring system 100 into the colon with advancementof the semi-rigid tube pusher 1703. In some embodiments, the flexibletubular membrane end 1711 that exits the central tube distally is fixedto the semi-rigid tube pusher 1703 so longitudinal traction on only theflexible tubular membrane end 1709 that is on the outside of thesemi-rigid tube is required to compress the anchoring system 100 andhold the anchoring system 100 to the semi-rigid tube pusher 1703. Insome embodiments, the flexible tubular membrane end that is on theoutside of the device 100 and semi-rigid tube pusher 1703 is fixed tothe semi-rigid tube pusher 1703 so longitudinal traction on only theflexible tubular membrane end 1711 that exits the distal end of thesemi-rigid pusher is required to compress the anchoring system and holdthe anchoring system to the semi-rigid tube pusher 1703. Once the deviceis positioned in place, the flexible tubular membrane 1704 can bedetached from the semi-rigid tube pusher 1703 and extracted from thepatient's bowels through the center of the semi-rigid tube pusher 1703by traction on the end 1711 of the flexible tubular membrane that exitsthe distal end of the semi-rigid tube pusher 1703. The semi-rigid tubepusher 1703 can then be removed from the patient once the anchoringdevice is activated with negative pressure.

In some embodiments, there is a releasable, fluid-tight, and detachableconnector that allows for removal of a length of the sheath outside ofthe body to allow for more easy delivery of the device. In someembodiments, the connector is located at 8 inches to 36 inches from theclosest sealing element. In other embodiments, the sheath is directlyconnected to the effluence bag or left open at 8 inches to 36 inchesfrom the closest sealing mechanism 110.

According to some embodiments, the device 100 has a removal system thatallows it to be removed as needed. Fluid or positive pressure can bedelivered down the pressure tube 112 to reduce the adhesive forcecreated to anchor the device 100. The device 100 can then be safelyremoved from the patient. In some embodiments, the device 100 isconfigured with a port so that fluid, (ex. Saline solution) can be usedto infiltrate tubing in communication with the foam and detach thesleeve 102 from the bowel wall. The fluid can be introduced into thepressure tube 112, or the device 100 can have a separate tube thatextends outside the patient's body to provide irrigation. It may bepreferable to use the pressure tubing for both negative pressuredelivery and irrigation. In some embodiments, the irrigation system isin fluid connection with the pressure tube, wherein the irrigationsystem introduces a fluid into the pressure tube for irrigation. Theirrigation through the tube can be used to wash out abdominal contentsthat may have leaked around the proximal sealing mechanism 108 and todetach the device 100 from the patient's bowel wall. By use of one ormore of these removal methods, the pullout force becomes negligible andthe device 100 can be removed without damaging the surrounding tissue.

Other Uses

The embodiments of the invention described herein may have uses outsideof protection of damaged bowel or anastomosis protection. For example,the disclosed device and method may also be used for continence controlin settings like an Intensive Care Unit. In these settings, fecalcontamination of the perineum can result in significant skin irritationand breakdown. Existing continence control devices for diverting fecalflow into a collection bag often result in complications such as fecalleaks, displacement of fecal tubes, and erosion into the bowel wall. Incontrast, the device and method described here can anchor a fecalcollection sheath within the rectum of a patient with an anchoringmechanism that is non-traumatic, sealed off from leakage, not easilydislodged, and easily reversible. The anchoring methods described hereinmay also be used to fixate other sheaths or drug delivery devices withinthe bowel. For example, sheaths for limiting absorption used fortreating metabolic disorders, diabetes, or obesity may be anchored usingthe described technique. Specialized sheaths designed to elute drugs mayalso be anchored using the described technique. For example, a sheathattached to the anchor device described herein can contain controlledrelease anti-inflammatory drugs to treat inflammatory bowel disease.Moreover, as described above and shown in FIGS. 18 and 19, a secondanchor element can be placed distally to create a sealed space betweenthe treated segment of bowel, the two anchor elements, and the sheath.This space can be filled with therapeutic solutions such as antibiotics,anti-inflammatory drugs, or chemotherapeutic agents for cancer. Thisallows for controlled local delivery to a segment of bowel wall isolatedbetween the two anchor elements. Also as previously mentioned, sheathsmay be anchored that may help with diverting flow from a damaged segmentof bowel such as a perforation within the bowel, ischemic bowel, bowelcontused by blunt trauma, or bowel that is inflamed or dilated such asin cases of inflammatory bowel disease.

The embodiments illustrated and discussed in this specification areintended only to teach those skilled in the art how to make and use theinvention. In describing embodiments of the invention, specificterminology is employed for the sake of clarity. However, the inventionis not intended to be limited to the specific terminology so selected.The above-described embodiments of the invention may be modified orvaried, without departing from the invention, as appreciated by thoseskilled in the art in light of the above teachings. It is therefore tobe understood that, within the scope of the claims and theirequivalents, the invention may be practiced otherwise than asspecifically described.

1.-30. (canceled)
 31. A delivery system for inserting an anchor into abody lumen that has a flow there through, a damaged tissue site, and anundamaged tissue site apart from the damaged tissue site, the deliverysystem comprising: (a) a semi-rigid tube pusher; and (b) an anchor thatengages with the semi-rigid tube pusher, the anchor comprising: i) asleeve having a sleeve lumen extending though the sleeve with openingson each end allowing the flow of the body lumen to pass through, thesleeve includes an inner side facing the sleeve lumen and an outer sideconfigured to contact the undamaged tissue site; ii) a sheath configuredto be in sealed fluid communication with the sleeve, such that an end ofthe sheath extends distal to one end of the sleeve and extends beyondthe damaged tissue site in order to cover and protect the damaged tissuesite from content flowing through the sheath and the sleeve; and iii) anegative pressure tube coupled to the sleeve and coupled to a negativepressure source, the negative pressure tube being configured to create anegative pressure seal between the outer side of the sleeve and theundamaged tissue site, while allowing the flow of the body lumen to passthrough the sleeve, wherein the anchor is configured to be pushed intoposition by advancing the semi-rigid tube pusher into the body lumen.32. The delivery system of claim 31, wherein the sleeve is compressibleby normal peristaltic forces of a patient's bowel.
 33. The deliverysystem of claim 31, wherein the anchor further comprises a first sealingmechanism disposed on a first end of the sleeve and a second sealingmechanism disposed on a second end of the sleeve.
 34. The deliverysystem of claim 33, wherein the first and second sealing mechanisms forma substantially airtight and fluid-tight seal with the undamaged tissuesite of the body lumen.
 35. The delivery system of claim 33, wherein thefirst and second sealing mechanisms comprise one or more tapered finsplaced in series on each end of the sleeve with an orientation directedaway from a center of the sleeve so that the one or more tapered finslie flat against the undamaged tissue site when negative pressure isdelivered through the negative pressure tube.
 36. The delivery system ofclaim 33, wherein the first and second sealing mechanisms comprise arounded protrusion or multiple protrusions placed in series that arecompressible.
 37. The delivery system of claim 33, wherein a diameter ofeach of the first sealing mechanism and the second sealing mechanism isless than or equal to a diameter of the body lumen at the undamagedtissue site.
 38. The delivery system of claim 33, further comprising aconnector tube coupling the negative pressure tube to the sleeve, theconnector tube extending through one of the first sealing mechanism andthe second sealing mechanism and having an opening on the outer side ofthe sleeve.
 39. The delivery system of claim 38, wherein the connectortube includes a one-way valve therein.
 40. The delivery system of claim33, wherein the sleeve, first and second sealing mechanisms, and sheathare comprised of one or more of silicone, polyurethane, thermoplasticelastomer, rubber, rubber-like material, or other polymer.
 41. Thedelivery system of claim 31, wherein the anchor further comprises asurface material disposed on the outer side of the sleeve, wherein thesurface material is a stacked mesh matrix, a honey-comb lattice ofinterconnected channels oriented in a radial fashion around the sleeve,a gauze, a fabric, a three-dimensional woven material, or open-cellfoam.
 42. The delivery system of claim 31, further comprising a flexibletubular membrane that encases at least the sleeve of the anchor.
 43. Thedelivery system of claim 42, wherein the flexible tubular membraneinvaginates down a proximal end and out a distal end of the semi-rigidtube pusher.
 44. The delivery system of claim 42, wherein the deliverysystem compresses the anchor and holds the anchor to the semi-rigid tubepusher when longitudinal traction is applied to the flexible tubularmembrane.
 45. The delivery system of claim 31, further comprising aflexible member that can be detached from the semi-rigid tube pusher andextracted from a patient's body through a center of the semi-rigid tubepusher after insertion of the anchor.
 46. The delivery system of claim31, wherein the sleeve lumen has a diameter between approximately 1 cmand approximately 6 cm.
 47. The delivery system of claim 31, wherein thesleeve comprises a flexible material having a Shore A hardness betweenabout 20A and about 70A.
 48. The delivery system of claim 33, whereinthe first and second sealing mechanisms comprise a flexible materialhaving a Shore A hardness between about 20A and about 70A.
 49. Thedelivery system of claim 31, further comprising the negative pressuresource, wherein negative pressure is applied to the negative pressuretube by the negative pressure source to maintain a constant negativepressure at a level between −50 mmHg and −200 mmHg.
 50. The deliverysystem of claim 31, wherein the sheath has a length that allows it toextend outside the body lumen.
 51. The delivery system of claim 31,wherein the sleeve has a length that is between about 3 cm and about 25cm.
 52. The delivery system of claim 31, further comprising a pluralityof negative pressure tubes in fluid connection with the outer side ofthe sleeve.
 53. The delivery system of claim 33, wherein the sleeve, thefirst sealing mechanism, and the second sealing mechanism form a firstanchoring element, with the anchor further comprising: a secondanchoring element in mechanical connection with the sheath, the secondanchoring element disposed apart from and distal to the first anchoringelement; and a port disposed between the first anchoring element and thesecond anchoring element, wherein the sheath, the first anchoringelement, and the second anchoring element create a sealed off spacebetween the first and second anchoring elements, the sheath, and thedamaged tissue site, and wherein the port is in communication with thesealed off space to allow access from outside the body lumen for fluiddelivery and withdrawal.
 54. An anchoring system, comprising: a sleevehaving an inner surface defining a first lumen, wherein the sleeve isconfigured to be disposed in a tissue cavity proximal to a damaged areaof tissue of the tissue cavity; a first sealing mechanism disposed at aproximal end of the sleeve; a second sealing mechanism disposed at adistal end of the sleeve; a pressure tube in fluid connection with anouter surface of the sleeve; and a sheath in connection with the sleeve,the sheath forming a second lumen, the second lumen being in fluidconnection with the first lumen of the sleeve, the sheath having an endin sealed fluid communication with, and extending distal to, a distalend of the sleeve and the second sealing mechanism, wherein the end ofthe sheath, extending distal to the distal end of the sleeve, isconfigured to cover and protect the damaged area of the tissue of thetissue cavity from content flowing through the second lumen of thesheath and the first lumen of the sleeve; wherein the anchoring systemis configured to apply negative pressure by an external negativepressure source to the pressure tube to form a sealed configuration ofthe sleeve that substantially prevents displacement of the sleeve in anaxial direction due to friction forces between (i) the outer surface ofthe sleeve and the first and second sealing mechanisms of the sleeve;and (ii) the tissue of the tissue cavity proximal to and at a differentlocation from the damaged area of the tissue of the tissue cavity, andwherein the sleeve, the first sealing mechanism, and the second sealingmechanism are compressible by normal peristaltic forces of a patient'sbowel.